A disquieting Aztec sculpture displays hundreds of stone skulls representing the victims of human sacrifice.

Part bookstore, part café, and part forest.

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

These azure waters were thought to lead to the Mayan Underworld.

A lovers' beach, tucked below the surface of the island, provides a safe haven for romance.

An enormous, 30-story-deep hole in the middle of Guatemala City.

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

Where dogs like the rare "Fire-Tailed Border Cocker" run free on the mountainside.

This tiny home was originally a narrow alleyway.

A massive underwater sinkhole made famous by Jacques Cousteau.

A cozy bookstore and coffee shop in the heart of Cartagena's Old City.

An oasis of shade and color amidst the bustle of the old city.

Known as the "Valley of the Moon," this Jordanian wadi is one of the most amazing desertscapes on Earth.

The deadliest diving spot in the world is also a stunning geological marvel.

An alien landscape of chalk-rock in the Egyptian desert.

An endless sea of white conical domes.

The celebrated eyesore created by starry-eyed sweethearts.

The headless bodies of more than 1,300 guillotined victims of the Reign of Terror are buried here in mass graves.

A surrealist timepiece by the artist of melting clocks.

This simple convenience store sits on the location where the Ouija board was named—and has a plaque to prove it.

A hidden alley in urban Baltimore is a haven for graffiti artists.

The site where Poe "in great distress, and ... in need of immediate assistance" likely died.

The man who first patented the Ouija board rests in peace beneath a headstone that playfully reflects that achievement.

This free, take-a-book shop seems like a trick but isn't.