Sacked by Vikings, blessed by William the Conqueror, dealt a fatal blow during the French Revolution—these ruins have seen it all.

The water-powered carriages are long gone, but for over a century this funicular railway has been the fastest route to the highest point in Paris.

This whimsical castle of grottoes was the labor of love of a French postman, and one of the greatest achievements of outsider architecture.

Exquisite wall sculptures carved in secret by an early quarryman in an obscure corner of the Paris Catacombs.

Walk upon the mementos of the dead in this Parisian courtyard paved with medieval tombstones.

This museum houses an imposing skeleton army comprised of creatures great and small.

A haunting collection of the vanished and disappearing natural world.

This 1,300 year old monastery built atop a single rock was once only accessible depending on the whims of the tide.

The oldest stone house in Paris was built by its most famous alchemist.

Abandoned railway line circling the city of Paris.

France's most famous cemetery, with some of its most curious tombs.

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

The depictions of slaughter are surprisingly detailed at this mysterious ancient site.

The shockingly unspoiled Peruvian tomb of the Lord of Sipan was once guarded by a footless warrior.

An abandoned Incan construction project left behind a mysterious "doorway."

After an epic flood washed away its enslavers, this city has been part ghost town, part cultural wildcard for the past three centuries.

A paradisical gorge with rapids, waterfalls, and wildlife whose raw beauty is the stuff of CGI movies.

An Archaeological Wonder of Peru, and the largest stone ruin site in the New World.

These delicate ruins need more tourists to keep them from fading away.

Extraordinary rock formations in open Peruvian fields.

These steeply terraced ruins are a stop along the Inca Trail to Machu Picchu.

The world's fifth tallest waterfall is a spectacular silver chute of water that cuts through the cloud forest in northern Peru.

If you’ve ever seen a picture of Machu Picchu, then you’ve seen a picture of Huayna Picchu—you just didn’t realize it.

One of the world's tallest waterfalls wasn't revealed to the world at large until 2006.