Explore the atmospheric ruins of an abandoned convent in the dense forests of Mexico's first national park.

Murals made with millions of colorful stones adorn the abandoned building.

A barbarous band of serpents guard the bases of these Aztec temples.

Pause in an abandoned hydroelectric station, now overrun with wildlife, to consider a thought-provoking poem.

Past the hills and beyond the graveyard, this church feels extremely out of place.

The earliest known map to show America, discovered by accident at a Paris bookshop.

This funky former tobacco factory is one of the most striking examples of Madrid's cultural diversity.

The morbid items in this small and hidden museum are not for the weak stomached.

Over two centuries old and counting, Madrid's massive botanical garden contains one of Europe's only desert environments.

A lush indoor jungle fills this bustling Madrid transportation hub.

This small and often-overlooked museum holds some of Spain's finest artistic treasures.

A small museum displays some of the artifacts discovered during a subway station renovation.

Strange masks and obscure costumes are housed in this old Madrid corrala.

A pair of gigantic baby heads greet passengers at Atocha Station.

Shrapnel, dynamite, bullets and Franco couldn't destroy this bust, rescued and kept hidden as a family secret for over 40 years.

The preserved arm of a third-century sorcerer is believed to have the power to lift curses and spells.

This modern labyrinth lies in the shadow of a ruined medieval castle.

One of Scotland's most important modern structures, it just made the '100 Most Endangered Sites' list.

Ruined castle with subterranean vaulted Goblin Ha' or "Goblin Hall."

Old-fashioned knowledge and modern engineering create the world's only rotating boatlift.

A scattered trail of street art adds a pop of color to the city's stark structures.

Largest lake in Great Britain measured by surface area.

Monty Python fans will recognize this abandoned mine as the Cave of the Killer Rabbit of Caerbannog.

Large-scale contemporary artworks tower over fields and lurk in forests around a Jacobean manor house.