Built in the 1940s as part of a secret fuel reserve facility, the Marsiling Tunnels were later abandoned and left to decay beneath the jungle. The dark, flooded passages have become infamous for eerie encounters: explorers report disembodied voices, footsteps echoing in the water, and sudden cold winds despite the tropical heat. Some stories link the tunnels to wartime executions during the Japanese occupation, claiming restless spirits still haunt the chambers. With their hidden entrances and oppressive atmosphere, the tunnels are considered one of Singapore’s most haunted urban exploration sites.