A jaw-dropping "megalibrary" that turns book-browsing into a geometric adventure.

An elaborate Mayan city shrouded in alien conspiracy revealed the tomb of Pacal the Great.

The stoutest tree in the world.

This beautifully deceptive waterfall is something far different from what it appears to be.

66,000 pieces of art, donated by one of the world's richest men.

Part bookstore, part café, and part forest.

Superstitious? Discover the witchy side of Mexico through its largest esoteric market.

The Cathedral of Salamanca has a number of unusual carvings but none so surprising as a modern astronaut.

Cliffside houses provide a spectacular view from their perch above the valley.

An underground city of salt.

A Red Cross memorial museum at the site of the Niš concentration camp that operated for four eventful years during World War II.

Structure built from the skulls of vanquished foes.

The bizarre rocks of Đavolja Varoš are the result of natural erosion.

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