The Round House sits on the small limestone bluff at the western end of High Street, looking out across the Indian Ocean. It is a twelve-sided, eight-celled gaol — the only one of its kind in Australia — and predates the founding of Fremantle proper by several years.
A volunteer is usually on duty between 10:30 and 15:30; entry is free. The view from the wall takes in the port, Bathers Beach, and the Ocean. The daily 1pm Time Ball drop and cannon firing draws a small crowd; stand back, the noise is louder than expected. Combine with a walk through the Whalers Tunnel underneath, the second-oldest tunnel in Australia.