It comprises a succession of connected streets, namely Castlehill, the Lawnmarket, the High Street, the Canongate and Abbey Strand.
It’s more than a mile long using current measurements, but it is roughly a Scots mile – a now redundant measurement which is 224 yards longer than the English mile used today.
The thoroughfare contains a wealth of historic buildings, including the former Tolbooth-Highland-St John's Church now used as the headquarters of the Edinburgh Festival, the Camera Obscura, the Assembly Hall of the Church of Scotland, Gladstone's Land, the High Court of Justiciary, St Giles' Cathedral, Edinburgh City Chambers, the Mercat Cross, John Knox's House, and many others.
It's also the location of the famous Heart of Midlothian, the pattern of cobbles that marks the site of the Old Tolbooth.
And every August it is taken over by street performers, actors and musicians as it becomes the epicentre of the Edinburgh Festival Fringe – with tourists packing the streets.
People have lived on the site of the Royal Mile for around 7000 years, but most of the buildings you can see today date back to the 19th century.
A smattering of far older buildings on the streets include St Giles’ Cathedral which was founded in the 12th century, John Knox House which dates back to 1490, Moubray House which was built in 1477, Huntly House which was completed in around 1570 and the much-photographed Canongate Tolbooth, from 1591.
These pictures aren’t quite so old, but provide a look at how the Royal Mile looked back in the 1950s and 1960s.
A message from the Editor:
Thank you for reading this article. We're more reliant on your support than ever as the shift in consumer habits brought about by Coronavirus impacts our advertisers.
If you haven't already, please consider supporting our trusted, fact-checked journalism by taking out a digital subscription.