Wishing Tree
Apparently people used to walk around the tree three times backwards and then make it wish, it was apparently a popular thing to do.
Plaque reads:
'This was the site of the Gardens first Wishing Tree, a Norfolk Island Pine. It was planted in 1818 at the request of Elizabeth Macquarie, the Govenor's wife. The tree was removed in 1915 when old age and decay threatened to topple it'
Submitted by @IanThorp