Although strictly speaking it's not quite a mile, the street between the castle and Holyrood Palace is Edinburgh's most historic. It is easy to spend the afternoon exploring the small alleyways off the main street, browsing in the shops, watching the street performers and visiting buildings like St Giles' Cathedral.
Just five minutes' walk from the castle, the National Museum showcases Scottish history from ancient times to modern feats of technology and engineering. Don't miss the famous Lewis Chessmen, dating from Viking times and the huge mammal collection in the natural history section.
Find all about life in the 1600s in the former home of a prosperous merchant, Thomas Gladstone. Book your guided tour in advance to experience the house and in particular the expensively painted Renaissance ceilings.