This attraction was abandoned after the Chernobyl disaster.

This medieval Italian town is a sheer (and beautiful) cliffside defense.

The underground sanctuary of a mysterious ancient Roman religious cult contains an exquisite traditional fresco.

A 2,000-year-old computer demonstrates remarkable engineering and astronomical precision.

Centuries before the modern seismograph, Armenian monks measured quakes with this tilting pillar.

An ancient instrument used to measure the waters of the Nile so Egyptian farmers would know whether to expect famine or flood.

The world's second-largest sundial, made entirely out of stone.

No telescopes, no power, no gift shop: The Observatory of Chichen Itza, one of the world's oldest observatories, takes astronomy back to basics.

Ancient Egyptian relief, claimed to depict an electrical light.

Numerical symbolism abound at East Asia's oldest observatory.

This punny mirror of another Wisconsin attraction is exactly what it sounds like.

Of the many chalices in the running for the Holy Grail, this one in Valencia Cathedral sure looks the part.

Sleep in a climate-controlled plastic bubble for the night.

Eulogizing an unknown man's unusual demise.

Mexico's astounding mummy museum with "the world's smallest mummy."

The largest cave shaft in the world is home to thousands of birds and popular with BASE jumpers.

The "world's smallest volcano" has been used to store meals and dispose of dead bodies.

The only museum with its curator—and her pets—buried inside.

Venice's island of the dead.

This Venice bookstore has resigned itself to constant flooding by keeping its books in bathtubs and boats.

A 500-year-old series of tunnels long believed to be folkloric was uncovered beneath the streets of Puebla.

The splendor of this 17th century golden chapel has led it to be called the "eighth wonder of the world."

This quaint Italian town keeps losing ground as the sides of its plateau slowly erode.

Sleep in a glass pod dangling off a cliff.