Every summer, throngs of tourists flock to the high altitudes and commonwealth-era landmarks of Baguio, a city built over the bones of a former R&R facility for American soldiers. But running underneath many of these frequented sites are a series of tunnels built during World War II by invading Japanese forces.

While most of this underground network has already been mapped out, some locals believe that somewhere beneath the former mining city lies one last treasure trove waiting for discovery: the fabled lost gold of Japanese General Yamashita.

When the Philippines became an American territory in 1898, American troops and bureaucrats stationed in and around Manila were eager for ways to escape the tropical heat. Baguio’s cool mountain air and moderate temperatures made it “the summer capital” of the Philippines.

The heavy American presence made the city a target when the Japanese invaded the Philippines in 1941 during WWII. During the Japanese occupation, their army built a series of tunnels under Baguio to store military supplies.

Today the mouth of one of those tunnels can be found in the Baguio Botanical Garden, a dark cavern beneath a cascade of ferns and foliage. The tunnels are pitch black and dank, forming an underground loop beneath the road above.

For years, rumors circulated that Baguio’s tunnels hid Yamashita’s storied stolen treasure. Rumors like these have cropped up at sites across the Philippines, borne of the vast amount of wealth looted by the Japanese.

In 1945, the city played host to the formal surrender of the Japanese Imperial Forces, marking the end of WWII. And it is perhaps this historical significance that has fueled the imagination of so many visitors searching for truth behind the myth.

There is perhaps a “fiction masquerading as truth” moment in the novel Cryptonomicon by Neal Stephenson.  The book concludes with an expedition into the mountains of the Philippines to hunt for a massive stash of gold.