Mussenden Temple

Where it sits. Mussenden Temple is a small domed rotunda standing on the lip of a basalt cliff near Castlerock in County Londonderry, about forty metres above the sand of Downhill Strand and open to the whole northern horizon. It is the eye-catcher of Downhill Demesne, the cliff-top estate laid out from the 1770s by Frederick Augustus Hervey, fourth Earl of Bristol and Church of Ireland Bishop of Derry from 1768 until his death in 1803 — a man remembered on this coast simply as the Earl-Bishop. From the temple the view runs west along seven miles of beach to Magilligan Point and across Lough Foyle to the Inishowen hills of Donegal; east it takes in Castlerock, Portstewart, Portrush and, on the clearest days, the far headland of Fair Head.

The story behind it. The temple was completed in 1785 and built as a library. Its plan came out of the Earl-Bishop's Italian travels: he described it as based on Bramante's Tempietto on the Janiculum in Rome, which in turn looks back to the circular Temple of Vesta at Tivoli, and the execution is generally credited to Michael Shanahan, the Cork architect and mason who accompanied him to Italy. The interior walls were lined with bookcases; a fire was kept burning permanently in the basement below, with a flue running inside the wall, so that even in this ferociously exposed position the books stayed dry. It is dedicated to the memory of the bishop's young cousin Frideswide Mussenden, who died in 1785 aged twenty-two, and whose relationship with him was the subject of comment at the time. Around the outside runs a line from Lucretius on the sweetness of watching another's struggles from safe ground — an epigraph aimed squarely at the shipping below.

The demesne around it. Downhill House, the Earl-Bishop's mansion, stands a few hundred metres inland as a roofless grey shell. It burned in 1851, was rebuilt, served as billets in the Second World War and was unroofed in the 1950s; walking through its empty window openings with the sea beyond is the most atmospheric part of a visit. The estate also keeps its walled garden, an ice house, a dovecote, a mausoleum and the elaborate Bishop's Gate at the Castlerock entrance, where a gardener's cottage sits beside a wooded ravine known as the Black Glen. The property has been in National Trust care since the 1940s, with paid admission to the grounds; the temple itself is normally open to walk into during the season, and has held a civil wedding licence since 2007.

On screen. The temple is the landmark above one of Northern Ireland's most-visited Game of Thrones sites, though it never appeared in the series itself. The beach directly below — Downhill Strand — played the shore of Dragonstone in the opening episode of season two, where Melisandre burns the wooden idols of the Seven and Stannis Baratheon pulls a burning sword from the pyre. The crew shot westward along the sand precisely so that no eighteenth-century rotunda would appear on the skyline of a fictional Targaryen island. Visitors making the connection in the other direction get the better deal: from the cliff-top railing you look straight down onto the stretch of sand where the scene was filmed.

What you actually see today. Erosion is the temple's permanent problem. It was once possible to drive a carriage right around the building; the cliff has since crept much closer, and in 1997 the National Trust carried out major stabilisation work on the face below to stop the whole thing going into the sea. The approach from the car park is across open grazed parkland, so it is grass underfoot with a gentle rise, exposed and often very windy — this is not a place for hats. Below the cliff, the Belfast–Derry railway runs through tunnels bored beneath the demesne, and trains emerge onto the shoreline in a way that has been photographed almost as often as the temple.

Getting there and timing. Castlerock railway station is about a mile and a half away, with direct services from Derry, Coleraine and Belfast, and a walk up through Bishop's Gate; by car the site is fifteen minutes from Coleraine and forty-five from Derry, with parking at Lion's Gate. The grounds open daily; the interior of the temple keeps shorter seasonal hours. Photographically the building faces the setting sun in summer, and the last hour of light with the beach wet below is the reason so many photographers wait around. Bring a windproof layer whatever the forecast, and allow ninety minutes to see the temple, the mansion ruin and the glen without hurrying.