The story of Edinburgh Castle

Research in 2014 counted 26 sieges in this castle's 1,100-year history, giving it a claim to being "the most besieged place in Great Britain". Edinburgh Castle sits on the plug of an extinct volcano that rose about 350 million years ago.

Cliffs guard the south, west and north, so the only easy approach is from the east, the way you still walk up today. There has been a royal castle on the rock since the reign of Malcolm III in the 11th century, and it remained a royal residence until 1633, while also serving as an arsenal, a treasury, a mint and a prison.

Few of its buildings pre-date the Lang Siege of 1573, when artillery largely destroyed the medieval defences. Look for St Margaret's Chapel, from the early 12th century and regarded as the oldest building in Edinburgh, and for the Honours of Scotland, the Scottish regalia kept here.