Yeah the Yamashida Gold. When the Japanese occupied south east Asia they ransacked temples, banks, museums, etc for gold and artifacts. Towards the end of the war it simply vanished. We don't know where. No one does.

The two main hypothesis are that it was smuggled into China and is hidden in a cave somewhere. My professor is Chinese so I asked him about this and he said it's totally possible. He also noted that the other explanation is viable--that it is somewhere in the Philippines.

A "historian" named Sterling Seagrave has written a few works on this. I put it in quotes because he backs nothing up with evidence like documents and the like. I wouldn't suggest reading his stuff for info about the gold.