This Soviet-era "closed town" was a top secret uranium producer often left off of maps.

One of the tallest waterfalls in Africa is also home to a population of monkeys who enjoy the waters and the occasional guest.

This amazing ancient cave was kept secret for seven years to protect it from the public.

A magical oasis in the middle of the Negev Desert.

The largest cave in Northern Europe.

A crypt believed by many Congolese to be a center of black magic.

Science fiction's grandfather has a fittingly marvelous tomb.

This ancient village and its adjoining cemetery have a beautiful history of death and remembrance.

These "anatomical machines" are only one of the many strange items in this Italian crypt.

Skulls from the plague of 1656 and World War II bombings are united by a cult dedicated to caring for the ancient dead.

An unusual "skull with ears" sits in the crypt of this small church tucked away at the end of a narrow alley.

This disappearing geyser has been attributed to witchcraft, but really it's all about rainfall.

An empty relic of the Moscow Olympics crumbles away in Estonia's capital.

A secluded art gallery hidden within the cellars beneath Tallinn’s medieval monastery.

The gutted remains of this Estonian mansion are a monument to a tragic love.

Mysterious craters may have been home to an ancient cult.

The ruins of an Estonian prison are drowning in the quarry lake where the convicts were once forced to work.