A less secret tunnel in a different fort on the Sino-Russian border (Photo: Lzy881114/Wikimedia)

Early in the 1930s, when Japan had invaded Manchuria and the Second Sino-Japanese War was on the verge of breaking out, a secret tunnel was created under the Chinese-Russian border. The tunnel was used to pass information between the two allies through World II. 

The tunnel was recently re-discovered, reports Russian media, citing a Chinese-language story from Xinhau Far Eastern news agency. An employee of China’s Dongning Fortress, which is right on the border, heard about the tunnel on a visit to North Korea, where he met a man who said he’d helped construct it. 

The tunnel is not far from a Russian city named Ussuriysk. It was first located on the Russian side of the border. It’s not quite clear how long, how safe, and how passable it is. But forget all that, and just think: secret tunnel!

Bonus finds: Giant dolphin statue, a mysterious mason jar, a 4-inch centipede that had been hiding in a teenager’s eara centipede that had been hiding 3,600 feet underground

Every day, we highlight one newly lost or found object, curiosity or wonder. Discover something unusual or amazing? Tell us about it! Send your finds to sarah.laskow@atlasobscura.com.