The 18th-century Castletown House is Ireland’s most notable country house, not least because it reportedly influenced the design of the White House in Washington, D.C. It’s just one of these 12 examples of significant buildings that are worth a visit in Ireland.

　　Earlier versions of the descriptions of these buildings first appeared in 1001 Buildings You Must See Before You Die, edited by Mark Irving (2016). Writers’ names appear in parentheses.

　　Known locally as Burt Chapel, St. Aengus’s Church stands at the head of Lough Swilly, 6 miles (10 km) west of Derry in County Donegal. The church dramatically echoes the Grianán of Aileach, a Bronze-Age hilltop fort that dominates the surrounding countryside, and it is similarly circular in plan. A tentlike roof rising to a conical spire, both clad in copper, tops two concentric circles faced in rough-hewn stone. A split in the two circles forms the entrance; the space inside houses confessional boxes and a sacristy.

　　There is a historical link between St. Aengus’s and the fort, which is believed to have been the palace of the northern Irish kings until the 12th century. St. Patrick is reputed to have baptized King Eoghan there in 441. Eoghan’s grandson Aengus built the first church at Burt and was later its patron saint.

　　Today’s church accommodates a congregation of 550 people. It was built to accord with the liturgical norms of the Second Vatican Council (1962–65), which changed the way services were celebrated. Previously the priest had his back to the congregation; now he said Mass facing them. The font and altar, designed by Imogen Stuart, are of Portland stone, the latter spotlit from a lantern in the base of the spire. A sculptured wall in cast concrete depicts the site’s history.

　　This masterpiece of Liam McCormick, completed in 1967, is regarded as the finest church built in Ireland since the Council. He had a natural instinct for landscape. Like his other church buildings, it provides a break with the prevailing Gothic and Italianate aesthetic, and it sits naturally in Ireland’s bleak west coast. Despite its avowed purpose, McCormick referred to the church as “my pagan building,” because of its overt debt to the nearby fort. In 2000, it was nominated as Building of the Century in a national Irish poll. (Brendan McCarthy)

　　The island of Skellig Michael, a pyramidal rock 714 feet (217 m) high, 8 miles (13 km) off the coast of County Kerry, is an outstandingly well-preserved early Christian settlement. It was declared a UNESCO World Heritage site in 1996. St. Fionán is thought to have founded the settlement in the 6th century, but the earliest written records date from the end of the 8th century.

　　The Skellig settlement is the most dramatic expression of the early Christian monastic belief that intimacy with God was best achieved in harsh and isolated settings. There are six slated, beehive-shaped cells, their drystone walls curving gradually inward, covered with corbeled-stone roofs. Along with two oratories and the monks’ garden, they stand on a terraced shelf at the island’s northeast pinnacle, 600 feet (183 m) above sea level, reached by winding steps from the landing stage below. At its largest, the community is thought to have comprised 12 monks and an abbot, but climate change in the 12th century forced the monks’ departure.

　　More recently, archaeologists found evidence of the remains of a hermitage near the Skellig’s South Peak, built on the ledges of a rock rising vertically from the sea below to a height of almost 700 feet (213 m); this was, in their words, “a place as near to God as the physical environment would permit.” (Brendan McCarthy)

　　Built for William Conolly, a man who had come from a humble background to become speaker of the Irish House of Commons and the wealthiest man in Ireland, Castletown House is the most impressive Palladian country house in the country. With its perfect proportion, it is even said to have influenced the design of the White House in Washington, D.C.

　　Plans for the building were initiated by Alessandro Galilei, who was in Ireland working for Lord Molesworth, but it was left to Irishman Edward Lovett Pearce to complete the designs. Pearce had met Galilei while on his Grand Tour and was also a great admirer of Andrea Palladio. The main body of the house is Galilei’s, but the particularly Palladian colonnades and pavilions at either end of each wing are those of Pearce.

　　Conolly was offered a title, but he refused it, saying he was happy to be the wealthiest commoner in the country. His heir, Tom Conolly, did marry nobility when he wed Lady Louisa Lennox. Just 15 years old, Lady Louisa was great-granddaughter to King Charles II of England, and it was she who oversaw the completion and decoration of the house, beginning in 1758. She took many of her ideas from English architect Sir William Chambers, who never visited Ireland but did publish his designs.

　　As with all great country houses, stories and legends abound, which make a visit to Castletown, which is in County Kildare, more than just a trip around a piece of architectural history. There is the beautiful but flawed Long Gallery, whose blue chandeliers were ordered from Venice. The room was decorated while they were made and shipped. Colors were hard to describe in a pre-photography era, however, and the blue of the walls never matched that of the Murano glass. (Gemma Tipton)

　　Adare Manor was the family seat of the earls of Dunraven and is set within 840 acres (340 ha) of formal gardens and parkland beside the River Maigue in County Limerick. The nearby village, also built by the Dunraven family, is one of the prettiest in Ireland. Building work on the manor began in 1832 and was completed 30 years later. It is likely that James Pain was the architect, despite the insistence of Windham Henry Quin, second earl of Dunraven and Mount-Earl, that he had carried on the work “entirely from my own designs and without any assistance whatsoever.”

　　The Great Gallery, inspired by the Hall of Mirrors at Versailles, is, at 132 feet (40 m), one of the longest in Ireland. Lined with Flemish choir stalls, the gallery also has a timbered roof and stained-glass windows, and the effect is almost monastic. The structure is a series of visual allusions to famous Irish and English homes that the Dunravens admired: a turreted entrance tower stands at one corner; there are 52 chimneys to commemorate each week of the year, 75 fireplaces, and 365 leaded-glass windows. During the Irish famine in the 1840s, building work provided vital employment for many villagers. In 1850 the third earl commissioned A.W.N. Pugin, architect of the Houses of Parliament, to design a dining room, library, and terrace. But Pugin was very ill by then, and his work was never fully executed. P.W.C. Hardwick completed the building.

　　Adare Manor is a fascinating evocation of early Victorianism, reflecting the personalities of the two generations of the family that built it. (Brendan McCarthy)

　　Newgrange Burial ChamberNewgrange, a UNESCO World Heritage site, is one of the finest examples in western Europe of a passage grave. It consists of a 36-foot-high (11 m) stone and turf mound, through which a narrow, slab-lined passage leads to a burial chamber. At the winter solstice, on December 21, a shaft of light shines through a roofbox at the entrance and along the passage to the tomb’s furthest recesses. The complexity of carvings on the stone walls suggests a religious significance; the design may be evidence of sun worship. The cremated remains of four or five people, laid on large stone basins and found when the tomb was excavated, suggest that only priests and rulers were buried there. The passage tomb is surrounded by 97 curbstones; the most impressive is the large entrance stone, which is covered in swirls and designs. Inside the large mound, there is a long passage leading into a chamber that branches off three ways. The corbeled roof inside the burial chamber is still watertight and supports an estimated 200,000 tons. Newgrange was completed c. 3200 BCE; it predates the pyramids of Egypt. Excavation has revealed evidence of human occupation in the area as early as the fourth millennium BCE. The immediate area is known as Brú na Bóinne—the Bend of the Boyne. The mounds at Newgrange, Knowth, and Dowth dominate the area. (Brendan McCarthy)

　　Glendalough Round TowerIn 1825 the Scottish novelist and poet Sir Walter Scott described Glendalough as “the inestimably singular scene of Irish antiquities.” One of the great monastic centers of Early Christian Ireland, its 103-foot-high (31 m) Round Tower is among the finest examples of its kind. Glendalough—in the original Irish, Gleann Dá Locha, “Valley of Two Lakes“—is situated in a remote corner of the Wicklow Mountains, 30 miles (48 km) from Dublin. St. Kevin settled in the valley as a hermit in the 6th century and later established the first monastery. The settlement grew rapidly; Irish monasteries were not merely religious buildings but also functioned as centers of economic activity. Eventually, as many as 1,000 people may have lived in Glendalough, some in the monastery, others in the lay community nearby.

　　The Round Tower dates from the 11th century, an era when marauding Vikings frequently launched raids on Ireland. It functioned as a bell tower, but it was also a place of safekeeping for manuscripts, relics, and sacred utensils. While Irish monks used round towers as places of safety when under sudden predatory attack, they were not ideal for this purpose. Some round towers were burned, along with their books and treasures. Glendalough’s tower originally had six timber floors connected by ladders, and it tapers inward toward a conical roof. Its top story has four windows, which face the cardinal points of the compass. Glendalough is the most perfect example of a ratio often found in Irish towers: its height is twice its circumference. Its door is some 10 feet (3 m) off the ground and was reached by a ladder. Such height was necessary to add strength to the base of the tower, as foundations were often shallow. The tower’s conical cap was restored in 1876, supposedly from its original stone. Today, the Round Tower has come to symbolize County Wicklow and its rural charms. (Brendan McCarthy)

　　Lewis Glucksman GalleryIreland’s most intriguing art space, the Lewis Glucksman Gallery, named for the Wall Street philanthropist who funded it, stands on a meadow beside the River Lee on the campus of University College, Cork. From a plinth of limestone and concrete, the building, completed in 2004 and shortlisted for the Stirling Prize in 2005, winds into the treetops in a series of dramatically cantilevered twists and turns, with limestone yielding to timber. Four interlocking galleries, stacked vertically, face variously toward the river, the city, and the university’s original Neo-Gothic quadrangle, which was designed by Sir Thomas Deane in 1854. The architectural focus is on the individual galleries rather than on an imposing entrance hall. The architects, Sheila O’Donnell and John Tuomey, both of whom worked with James Stirling in the late 1970s, were influenced by a museum exhibit of a Viking ship raised on stilts and by an image from a poem by Seamus Heaney, Ireland’s Nobel Prize–winning poet, of a celestial ship floating above the monastery of Clonmacnoise, “big hull rocked to a standstill.” For Tuomey the building resembles a “celestial vessel straining over a stone terrain.” The Glucksman Gallery is highly sympathetic to its surroundings. It is clad in limestone at various levels, and the hardwood wrapped around the building mirrors its woodland setting. Existing trees were kept, and the building itself was held at tree-height. (Brendan McCarthy)

　　The Casino, 3 miles (5 km) northeast of Dublin city center, is an architectural gem. Ireland’s first and most important Neoclassical building was designed by Sir William Chambers as a garden pavilion for the Earl of Charlemont’s Marino estate, of which it is now the only surviving part. It was completed in 1762. It is deceptively small—only 50 square feet (15 sq m) to the outer columns. From the outside it appears to be a single-roomed, single-story Greek temple. Inside, however, there are 16 exquisitely proportioned rooms on three floors. Chambers, who originally intended his design as an end pavilion for Harewood House in Yorkshire, England, never visited Ireland.

　　Lord Charlemont, an Irish patriot, was a connoisseur of the arts, and the Casino is emblematic both of his aesthetic and political aspirations. In plan it is a Greek cross with each projecting elevation framed by a pair of columns. The main facades are north and south—with the entrance on the north—and are dominated by the solid attic story, statues, and urns. The urns were once functional chimneys, while the freestanding columns were hollowed out to conduct rainwater from the roof. Inside, the saloon is a more attractive space than the extravagant stateroom. Its ceiling’s centerpiece is a head of Apollo emerging from a sunburst. Also charming are two smaller rooms, the China Closet and the Zodiac Room. (Brendan McCarthy)

　　The Custom House, built at a cost of $390,000 (£200,000), encapsulates a brief moment of political confidence in 18th-century Dublin, when it acquired the architectural qualities of a capital city. Designed by architect James Gandon, it is probably the city’s most important public building. Completed in 1791, it stands on the banks of the River Liffey on Custom House Quay, to the west of the present-day port. Elegantly proportioned, with a long classical facade of graceful pavilions, arcades, and columns, its central dome is topped by a 16-foot-high (4.8 m) statue representing Commerce; 14 keystones over the doors and windows represent the Atlantic Ocean and 13 Irish rivers. The Custom House’s four facades are richly decorated with sculptures and coats of arms by Agostino Carlini, Thomas Banks, and Edward Smith. Gandon himself was the most influential Irish protagonist of Neoclassical style.

　　Dublin’s merchant class opposed the building of the Custom House, foreseeing that the chosen location, on reclaimed land, would move the city’s focus to the east, away from its medieval nucleus. Initially the Custom House was the headquarters of the Commissioners of Customs and Excise. Today it houses Ireland’s Department of the Environment. The original interiors were destroyed during the Anglo-Irish War (Irish War of Independence) in 1921. The dome of the Custom House was reconstructed by the Irish government after independence, using Ardbraccan limestone, which is noticeably darker than the Portland stone used in the original. The building underwent further restoration in the 1980s, when a new Portland stone cornice was put in place to replace the substandard one fitted after the fire. (Brendan McCarthy)

　　The 400-year-old campus at Trinity College is full of architectural gems, with the grandest buildings clustered around Front Square and stretching back past the Campanile to Library Square beyond. Behind these, contemporary architecture finds its place, with an impressive mix of styles and periods sitting alongside the gardens and cricket greens. Built in the early 18th century, the massive Long Room—also known as The Old Library—once dominated views of both college campus and city. The main construction is the work of Thomas Burgh, son of a bishop, and also responsible for the Royal Barracks in Dublin. Originally designed with open colonnades at ground level, these were enclosed in the 19th century to create more space for scholars and books. The defining addition, however, came in 1858–60 when Irish duo Thomas Deane and Benjamin Woodward removed the original flat roof, giving the building its beautiful, wooden, barrel-vaulted ceiling. Known for both drama and Neo-Gothic whimsy, Deane and Woodward’s work can also be seen next door in the wonderful Museum Building and in the Museum of Natural History in Oxford, England. At 210 feet (12 m) in length, the Long Room at Trinity became the largest single chamber library in the world, and it houses 200,000 of Trinity’s oldest books in its oak cases. (Gemma Tipton)

　　Dublin Central Bus StationDublin Central Bus Station, or Busáras, is one of the first postwar examples of the International Modern style in Europe. The architectural team led by Michael Scott was strongly influenced by Le Corbusier’s Maison Suisse in Paris. The bus station faces James Gandon’s Custom House—Dublin’s finest 18th-century building—and mirrors its use of Portland stone. Busáras was controversial at the time of its construction, in the early 1950s, because of its heavy cost. Standing on an island site flanked by three streets with facades of equal detailing, there are four distinct sections: two rectangular office blocks, a top floor pavilion, and the station itself, which is irregularly shaped. The bus station, a curved block capped by a wave-contoured, cast concrete canopy, emerges from beneath the two office buildings and appears to link them. This canopy, cantilevered out into the forecourt far enough to cover the passengers, was exceptional for its time. Busáras integrated art with architecture, meticulously detailed as it was with stone, mosaics, handmade bricks, and assorted woods. It incorporated a basement theater and a restaurant on the top floor. Scott’s visionary project failed, however, due to a lack of funding to exploit the building’s potential. The theater and restaurant closed, and the building became drab. Now a listed building, however, its iconic status is being belatedly recognized. (Brendan McCarthy)

　　RTÉ Campus HeadquartersThe Dublin campus for Ireland’s national television and radio broadcasting company, Radio Telefís Éireann (RTÉ), represented a new level of aspiration for Irish architecture and a visible expression of the Irish state’s rhetoric of modernization. The original building, phase one of the Television Centre, was constructed as the country emerged from a recession in the 1950s with an emigration crisis that had shaken national confidence. However, the RTÉ campus asserted a new optimism in Irish life and echoed the admiration of its architect, Ronnie Tallon, for Miesian ideals.

　　The architectural firm Scott Tallon Walker, which dominated Irish architecture for most of its existence, designed various buildings for RTÉ for more than 40 years. Here, the campus ideal finds a more complete expression than at most universities. It has a pleasing village intimacy, with Tallon’s designs showing his belief in the concept of expandable buildings.

　　On the north campus, the Radio Centre’s offices and studios are housed in a purpose-built building. Its many studios are below ground level for extra soundproofing, while production staff work in open-plan offices on the upper floor. An orchestral studio with a public gallery penetrates the two levels, and the lower-level studios are grouped around a sunken garden, which is also a source of natural light. (Brendan McCarthy)