From a revolutionary war era ship hiding under the streets of Manhattan, to a sprawling Roman villa unearthed in the backyard of an English home, or even an ancient Grecian maze long thought to be a myth--the strange structures uncovered in this episode sometimes lead to more questions than answers. 

From priceless treasure found inside a lost city, to an ancient manuscript hidden behind a wall, explore mysterious secrets lost deep inside various unseen chambers, like tunnels, caves, or even burial sites.