The Secret Underground Places That Feature In ‘Hidden, Forbidden & Off-Limits’ Posted on March 30, 2023 By Charlielikes The secret bunkers and fascinating underground locations across the UK that feature in Steve Higgins’ urban exploration book, ‘Hidden, Forbidden & Off-Limits’. Paranormal Tags:“that, billy wilkins, feature, forbidden, hidden, in, off-limits’, paranormal, places, secret, the, underground