Is Adelaide Gaol haunted?
Australia Reported haunting level 3 of 5

What actually happened
The first public hanging took place in November 1840 while the gaol was still under construction, and 45 people were executed and buried within its grounds before it was decommissioned on 4 February 1988.
The history
Built from 1840, Adelaide Gaol held about 300,000 prisoners over 148 years and is now managed by National Parks and Wildlife Service South Australia.
What people report
Volunteers and visitors have reported footsteps, voices and shadowy figures in the cell blocks, and the gaol hosts its own Halloween night event.
That paragraph is reported tradition, not a claim about what is there. The history above it is sourced; the stories are recorded because people tell them.
Visiting
18 Gaol Road, Adelaide SA 5000, Australia