Cave Rock is an unusual volcanic formation on Sumner Beach. For many years it has provided a playground for Christchurch children visiting the beach. Māori call the rock Tuawera, and say that it represents the carcass of a legendary whale washed up on the beach.
The stone hut on top of the rock was built in 1898. The signal has a long history with the Sumner community. It was originally used to signal vessels approaching the Sumner bar on their way to unload cargo at a wharf in Ferrymead.