A vanished Neolithic structure in an Irish farmer's field, an ancient oasis in the remote reaches of a Chinese desert, a centuries-old buried treasure in the U.K. and a dreaded predator in the Pacific Ocean are discovered by accident using drones.

Unlock military secrets from the air; spot a Nazi weapon designed to turn the tides of war in France; a covert Russian military tower in Chernobyl's shadow; a rumoured nuclear lab buried in Australia; a hush-hush surprise underneath Alcatraz.

Over a hundred big concrete arrows scattered across the U.S.; a giant chalk figure with an oversized phallus on an English hillside; a mysterious hole in the middle of a lake in Southern California.

Parting the waters using satellite imagery to see what lies beneath; discovering a lost-lost Turkish basilica, a church spire amid toxic sludge in Romania, a ship hull in the North Sea, a shocking underwater find that rivals the Great Barrier Reef.

Evidence of female power in ancient Kush; secrets long buried in a New Mexico pueblo; a find near the Nazca Lines in Peru; mysteries in Cambodia's Angkor Wat.

Strange markings in the remote reaches of Northern Finland; drones find a Manhattan-sized mystery in the depths of a Vietnamese cave; secrets are no longer hidden in the Antarctic; a lost sky-high world in Mozambique gets a visit from above.