An extraordinary "City of Caves" carved from solid stone.

An architectural marvel that combines Gothic architecture with Indian elements.

Two gushing waterfalls of hot spring water within a block of each other.

The vast, legendary catacombs hold secrets much stranger than stacked bones.

This 200-meter-high waterfall marks the site of Achilles’s immortal baptism at the mouth of the River Styx.

Along the most northwestern point in Africa is an ancient cave surrounded by legends.

Dedicated to the art of hunting, with juxtapositions of contemporary art.

The former home of a disgraced local priest now hosts a mysterious secret supper club.

The largest oak in England is said to have been the hideout of Robin Hood and his Merry Men.

The hidden lair of an alchemist rediscovered in a 2002 flood.

The underground mall's skylights look like they could be part of a spaceship.

Worm salt and other local ingredients are on the menu at this cult favorite ice cream shop.

Japanese gardens dedicated to the Japanese farmer that refused to throw in the trowel.

Deliciousness abounds at a Guatemalan restaurant masquerading as a pizzeria.

An enormous, inside-out glass globe built in 1935.

Living fossils in this remote Australian bay provide a glimpse of what Earth may have looked like 3.5 billion years ago.

A dark tunnel leads to a striking white crater that seems to be from another planet.

The "Bridge Over the Atlantic" lets you cross the waterway in mere seconds.

The hidden "ballroom" under a mansion lake was built by a criminal who ate a cyanide pill during his trial.

Mural made of 100,000 pieces of hand blown glass, and until recently, the largest glass mural in the US.

This hotel is an amazing example of the Escuela Tapatía de Arquitectura movement.

At a museum of everyday objects, it is the act of collecting that is really on display.

The now-public home of a renowned art collector is full of unique pieces from viceregal and 19th-century Mexico.

A jewel of the Mexico city skyline now slowly crumbles after surviving an earthquake.