The islands are still home to a small working population.
They are maintained by the National Trust for Scotland, in partnership with Scottish Natural Heritage and the Ministry of Defence.
The islands are recognised as a special site for wildlife.
St Kilda forms the most important seabird breeding station in north-west Europe.
Every year, thousands of gannets, fulmars and puffins nest on the towering sea stacs that rise out of the Atlantic Ocean.