Eilean Donan Castle, Dornie, Wester Ross, stands strategically on a small island at the mouth of Loch Duich.  Dating from 1220, and built by Alexander II in order to repel Vikings, the castle is one of Scotland's most photogenic and most photographed ancient monuments.  This particular photograph shows the castle floodlit by night on a very calm Loch Duich.

A print of this costs $25 (£16)