The Corkscrew Tree

I saw this while visiting the gardens of the late Vita Sackville-West's home at Knole today. I am sorry to say that I don't know the type of tree, but I was completely suprised by the way the bark describes a corkscrew shape over its years of growth. This picture can't convey how magical it appears to be. I guess the tree's age will be measured in hundreds of years (but I am no expert).