Edinburgh Castle

The castle sits on a plug of volcanic rock that drops sheer on three sides, so it looms over the city from almost every street in the centre.

Inside the walls it is less a single building than a small town of chapels, batteries, halls and museums layered over nearly a thousand years.

At one o'clock most days a gun is fired from the ramparts, a tradition that still makes first-time visitors jump.

From the upper batteries the view sweeps over the Old Town roofs, the New Town's grid and out to the Firth of Forth beyond, with the hills of Fife and East Lothian appearing on a clear day.

Edinburgh Castle occupies a dolerite volcanic plug rising 80 metres above the Old Town, its natural defences augmented by successive monarchs from David I to the Covenanters, making it simultaneously Scotland's most fought-over landmark and its most visited paid attraction.

The castle has served as a royal residence, military garrison, prison and treasury, and was the birthplace of Mary Queen of Scots in 1542, an event whose consequences — her forced abdication and flight to England — shaped Scottish politics for a generation.

The Great Hall, rebuilt in the early 16th century by James IV, remains one of the finest secular medieval interiors in Scotland, its hammer-beam roof and absence of internal columns creating a single vast space used for state ceremonies and banquets.

It is the defining symbol of Edinburgh and one of the most besieged and fought-over castles in the whole of Britain.

It holds genuinely important things: the Honours of Scotland, the Stone of Destiny and the tiny 12th-century St Margaret's Chapel, the oldest building in the city.

The setting on the volcanic rock, with the long slope of the Royal Mile falling away below, is as memorable as anything inside the walls.