Edinburgh Castle is an ancient stronghold which dominates the sky-line of the city of Edinburgh from its position atop Castle Rock. It is Scotland's second-most-visited tourist attraction. Human habitation of the site is dated back as far as the 9th century BC. As it stands today though, few of the castle's structures pre-date the Lang Siege of the 16th century, with the notable exception of St Margaret's Chapel, the oldest surviving building in Edinburgh, which dates from the early 12th century.
Courtesty of Wiki