A crumbling hospital from the 1850s on Roosevelt Island.

An "inside out" building in the historical center of Paris, featuring Europe’s largest modern art museum.

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

This iconic Parisian bookstore doubles as the "Tumbleweed Hotel" for traveling writers.

A "simple-hearted artist" turned an isolated Icelandic valley into his own art museum.

The picturesque birthplace of Icelandic democracy is drenched in the blood of its brutal past.

Iceland's tribute to its thankless civil servants.

This stunning concert hall has become a symbol of Iceland's national recovery.

Iceland's largest geothermal mud pool is a little bit haunted and a little bit dangerous.

If a glacial river suddenly diving into a sheer chasm via a dramatic, multi-stage waterfall isn't peak Iceland, it's certainly close.

This valley of hot springs and boiling mud pots is home to the record-holding "Geysir," which originated the English word.

Every summer local children form "pysja patrols" to save young birds that have wandered from their nests.

An encyclopedic collection of mammal penises.

One of the tallest buildings in Iceland, and perhaps, the most visually impressive.

This eye-popping Icelandic crater lake is surrounded by red volcanic rock.

The unique waterfall in Iceland's south features a backdrop of geometric black lava columns.

Medicinal spa created from the mineral-rich runoff of a geothermal power plant

This only museum in the world dedicated solely to mushrooms.

A World War II evacuation tunnel turned into a history display of Croatian state and people.

A peculiar museum that includes many drunken tales, a drunk driving simulator, and much more.

Where the lovelorn find a home for their sentimental keepsakes.

A graceful natural rock formation stands astride the point where the Gulf of California meets the Pacific Ocean.

This strange sculpture of a menacing skull surrounded by sun rays was discovered at the foot of the Pyramid of the Sun.

The winter home of millions of migrating monarch butterflies.