Syonan Jinja
Within the thick jungle of the MacRitchie Reservoir in Singapore lies the ruins of Syonan Jinja. Syonan Jinja was built during World War II by British and Australian POWs to commemorate the Japanese soldiers killed in the Battle of Singapore. Syonan Jinja is believed to be a replica of the Yasukuni Shrine located in Japan. The temple was destroyed by fire after the war ended, leaving it in ruins as it stands to this day. Over the years, the dense jungle began to overtake the ruins.
The fountain still stands today, but there was a secret tunnel found under it that seemed freshly dug. It is unknown who dug this tunnel up and what these people were looking for exactly. However, there is a conspiracy theory that Syonan Jinja was destroyed by the Japanese and not the British. This was because they were covering up a secret treasure buried in there during a retreat. Another rumor is that there was a group of Japanese Imperial Guards who were so loyal to the Emperor, they vowed to look over Syonan Jinja with their own blood.
This would indicate that a mass ritual suicide took place at the site. This act is called Sappuku. In 1981, a gardener named Sappari claimed that the Japanese had something valuable in Syonan Jinja. Just before the Japanese defeat in World War II, he described the Japanese soldiers going to the site and performing a lot of unseen activity. The access path to Syonan Jinja is almost completely blocked off by mother nature. There is even water to cross to reach the site, not to mention all the snakes, spiders, and mosquitoes that inhibit the area. Many people get lost and disoriented trying to get there, and these people blame it on the haunting of Japanese spirits who protect the site from outsiders. Crazy, huh?
(Source: Belanger, Jeff. Encyclopedia of Haunted Places. 2005.)