A small rock stack appropriately named 'Castle', very close to the legendary Little Mangere Island. This area is located 800 kilometres east of New Zealand's South Island, off the west coast of Pitt Island, within the Chatham Islands group.

Little Mangere was once the last refuge of the few remaining Black Robin until they were transferred to nearby Mangere Island and South East Island/Rangatira, as part of a species recovery plan in the early 1980s.