The land is full of geologic eye candy, such as otherworldly spires, mushroom-shaped hoodoos, and prehistoric fossils.

In a 345-million-year-old cave that's 200 feet underground, dinner awaits.

There is a small island in the Gulf of Nicoya where the only human inhabitants are dead.

This neon blue river gets its color from a unique mix of bacteria and volcano minerals.

Rock-cut cave complex filled with ancient Buddhist artwork.

This complex of vertically-excavated Buddhist, Jain, and Hindu monolithic temples in India's Maharashtra providence illustrates a spirit of tolerance characteristic of ancient India.

Accessible only at low tide, the deserted island is dotted with World War II ruins.

The highest peak in the United Kingdom has a history of physics, specters, and a pilgrimage of strange objects.

The most iconic structure in Scotland has been home to bishops, colonels, and Sean Connery characters.

This ruined fortress was the stronghold for a persecuted medieval leader and his infamous Assassins.

Sloth rehabilitation center in the jungle of Costa Rica.