Boab Prison Tree, Derby, Heritage site in Derby, Australia.

The Boab Prison Tree is a 1,500-year-old Adansonia gregorii with a girth of 14.7 metres, standing 6 kilometres south of Derby, Western Australia. Its massive grey-brown trunk is deeply pitted and widens at the base, with a large dark hollow opening low on the front. Green leafy branches rise above, and a low wire-and-post fence crosses dry reddish ground in front.

Herbert Basedow documented the tree during his 1916 Kimberley expedition and noted that human bones inside indicated Aboriginal burial practices. This observation helped later visitors see the hollow trunk as a place of cultural importance.

Aboriginal communities of Western Kimberley refer to these trees as larrgadiy in their Nyulnyulan languages and regard each one as an individual being with its own character. This traditional perspective recognizes old specimens as living personalities woven into the country's story.

A fence around the tree prevents vehicles from compacting the ground and protects the structure from damage caused by heavy foot traffic. Access on foot remains possible, though visitors are asked to keep some distance to avoid stressing the roots.

Despite widespread belief that the tree served as a temporary prison for Indigenous people, no records exist in historical sources to support this claim. The narrative appears to have emerged later and reflects myth-making rather than documented facts.