The Birnam Oak and its neighbour the Birnam Sycamore are thought to the sole surviving trees of the great forest that once straddled the banks and hillsides of the River Tay. This forest is celebrated in Shakespeare's Macbeth as the famous Birnam Wood.
The prophecy of Shakespeare's three witches did come true, with the branches of trees from great Birnam Wood, nearly 1,000 years ago, camouflaging the advancing army against Macbeth. It is believed that Shakespeare got inspiration for this section of `The Scottish Play` during a visit to Perth, Birnam and Aberdeen in 1599 as one of a troupe of comedians. The visit was arranged after King James VI sent a request for entertainers to Elizabeth 1.
Both trees look medieval. The lower branches of the gnarled and ancient Birnam Oak rest on crutches and the first three metres (10ft) of the trunk are hollow. The Birnam Sycamore, alongside, is thought to date back around 300 years old and has particularly impressive buttress roots. Both trees appear in the list of the one hundred Scottish Heritage Trees.
