This maze-like slot canyon is a unique gem within an already fascinating geological area.

A 300-yard long natural tunnel runs through a ridge deep in the Appalachian Mountains.

Originally built as a promotional giveaway, this suburban house was designed to be an IRL version of the Simpson home.

This institution collects the history of burlesque dancing with a titillating collection of ephemera and pasties.

The neon signs from Las Vegas' past find their final resting place at this unusual graveyard.

The Cycladic architecture makes this Athens neighborhood feel like an island paradise hidden in the shadow of the Acropolis.

Poseidon? No one seems to know.

This town named for the ancient God of War is home to fewer than a thousand people, but it's the birthplace of the Greek Revolution.

Seventeen oak trees sprout from the roof and walls of this tiny chapel without any visual evidence of roots.

This ancient hydrological marvel is now the base of a modern outdoor cinema.

A spectacular cave and a beguiling lake.

The hallucinogenic center of the ancient world.

Monasteries on rock pillars, once accessible only by frayed ropes.

A deserted island in southwest Japan that once sheltered persecuted Christians.

The best place for scenic views of the DMZ and North Korea.

This former coal mine has been turned into a sprawling modern art complex.

The cathedral stands in New Jufa, Isfahan's Armenian quarter that was established in 1606.

Named after a legendary garden called Eram in southern Arabia, built by order of Shaddad, an Arab king who wanted to compete with Paradise.

The fire inside this temple has burned for more than 1,500 years.

In this tiny Iranian town playing on the roof isn't just encouraged, it's the only place to go.

These little castles each held thousands of pigeons.

This vast, water-filled underground labyrinth can only be toured by boat.

Hydraulic systems in an ancient underground Iranian city.

A sophisticated astronomical tower built by one of the greatest Persian scholars of the Islamic Golden Age.