This is the 'sister-cache' to nearby Anika's Amazing Loot. Not surprisingly, it's been placed by Anika's little sister.
You are looking for a mint tin in Margaret Reserve, one of many tiny but cute parks around the area. Its hidden in a grand old fig tree perfect for climbing. The park has lots of shade, seats and a great playground for the kids. The cache contains a pencil and logbook, and some initial small swaps.