The largest of the remote island group of St. Kilda, Hirta (Gael: Hiort, perhaps derived from h-Iar-tir, "the west land") lies in the Atlantic 41 miles (66 km) northwest of the Outer Hebrides and extends to 637.4 ha (1575 acres). Owned by the National Trust for Scotland, its dramatic stacks and towering cliffs of gabbro and granite provide a backdrop to the sheltered village (Am Baile) on Village Bay which was abandoned in 1930 when the island's people were evacuated to the mainland. Following this evacuation, modern sheep were also cleared from the island and a number of the ancient flock were brought from Soay to ensure the survival of that species. In 1982, a small museum opened in one of the former houses on Village Street. A further distinctive feature of the island are its cleits; hundreds of small stone-built structures which stretch from Am Baile almost to the summits of the towering hills which surround it. These were built as store-houses, constructed of loose rubble to allow the wind to blow through, cooling and drying everything from sea-bird carcasses for food to peats for fuel. The Village and cleits together represent one of the largest groups of unaltered vernacular buildings in Britain.
The island's population was devastated by a smallpox epidemic in 1727, with most of the adults succumbing to the disease. Once the disease had runs its course, the Laird arranged for Hirta to be repopulated from Harris. In 1746, Government troops came to the island in their search for Prince Charles Edward Stuart (1720-88). Unsure of the reason for this 'invasion', the islanders fled their homes to hide in the hills, but it soon became clear that they knew nothing of the Prince and the troops left. During the First World War the island became a lookout and communications post, with around twenty naval ratings billeted here. On the 15th May 1918 a German submarine appeared in Village Bay and shelled the wireless station causing some damage to houses. Three weeks later the same submarine returned, but on this occasion was engaged by an armed trawler. During the Second World War, St. Kilda lay within an air-training area which unfortunately gave rise to several crashes on the islands; those who were killed are commemorated by a memorial in the church. The Ministry of Defence leased an area of the island in 1957 to build a tracking station working in conjunction with the missile testing range on South Uist. Temporary buildings were replaced with more permanent structures in 1969-70 and the pier was extended at a cost of £0.5 million. The site is now run by QinetiQ on behalf of the Ministry of Defence, with a resident staff of around 15.
Summer visitors can stay with permission from the National Trust for Scotland, although landing yachts are subject to restrictions to prevent the arrival of alien species, particularly rats. The highest peak is Conachair which rises to 430m (1400 feet).
