St Kilda – Official National Trust for Scotland website.
St Kilda is a World Heritage Site and a National Nature Reserve. The isolated archipelago lies 40 miles (64 kilometres) west-northwest of North Uist in the North Atlantic Ocean. It contains the westernmost islands of the Outer Hebrides of Scotland. The largest island is Hirta, whose sea cliffs are the highest in the United Kingdom. There are three other islands: Dùn, Soay and Boreray.