A floating cat sanctuary on an Amsterdam canal.

An actual 1957 Cadillac De Ville, encased in 15 cubic yards of concrete.

This abstract sculpture is rumored to cast a hammer-and-sickle shadow once a year.

One of the largest pieces of scientific equipment ever carried on a NASA space shuttle sits in a Chicago alley.

Former meatpacking facility turned vertical farm and sustainable business complex.

Nonprofit art center that promotes outsider, intuitive, and self-taught art.

Berry Gordy Jr.'s old home was the original headquarters of Motown Record Corporation.

A wacky two-story folk-art assemblage of carved and found objects, with lights, motion, and sound now in need of financial support.

This feline raises a friendly paw at drivers barreling toward the freeway.

Full-scale dinosaurs dominate the forested park in the middle of Chile’s second city.

The library's graceful rotunda is like a bibliophile's temple.

Remains of Roman amphitheater hidden in a sleepy quarter of Paris.

A lone cannonball remains lodged in the walls of the Hotel de Sens as a sober reminder of a revolution.

An overlooked marble is the only surviving in-place 18th century example of the measurement that changed how we define distance.

Down a cobblestone alleyway is a museum dedicated to Romanticism, with a secret garden.

Stroll through retro Paris while shopping for old postcards and discarded doll heads.

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

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

Where the sleeping monsters of Scotland's oil industry are left to rust.

A rotating bridge that carries a little canal over a larger one.

The world's largest secondhand book market is a haven for bibliophiles and bargain hunters.

All of Chicago's wood-paved streets are long gone but two alleys remain.

What was once the second largest steel mill in the US is now a sprawling complex of modern ruins.

Natural stone arches form a walkable "cathedral" at low tide, then disappear entirely when the water returns.