A horde of stray cats rule in this secluded Parisian cemetery under a bridge.

Paris' linguistic guide to the international language of, yes, love.

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

The history of radiation is on safe display at the foot of a radiation science laboratory.

An ancient system of freshwater caves filled with animal bones, including that of species long-extinct.

The winter home of millions of migrating monarch butterflies.

Diego Rivera's massive tiled fountain and failed infrastructure project.

A magical sinkhole on the Yucatán Peninsula is adorned with mini waterfalls and hanging vines.

An Aztec temple, the largest man-made pyramid in the world, sits buried in earth with a Spanish church set on top.

Underwater art project will double as a massive artificial coral reef to help regenerate the damaged ecosystem.

Twelve natural mummies are displayed in the crypt of this former monastery school.

Extraordinary sculpture garden created by an eccentric English poet.

High atop a Mexican rainforest mountain, this ancient pyramid once drew pilgrims countries away.

No telescopes, no power, no gift shop: The Observatory of Chichen Itza, one of the world's oldest observatories, takes astronomy back to basics.

The famous artist couple lived and worked here, in two different houses separated by a bridge.

Part bookstore, part café, and part forest.

A gargantuan crystal kingdom.

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

Frida Kahlo's childhood home, now a museum of her life and works.

A vintage penny arcade hidden in the back of a fun fair-themed bar.

This memorial to the thousands of Indian dead during WWI was callously used for target practice during WWII.

The remnants of a strange stilted building on rails can still be seen at low tide.

This concept building is the UK's first attempt at making a permanent structure of nothing but trash.

Half-drowned wooden stumps and stone blocks are all that remain of a Victorian landing that was destroyed by storms.