These ominous lava formations were said to be an entrance to the netherworld so of course they inspired a famous metal band.

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

The oldest (maybe) swimming pool in Iceland is a stunning oasis built into the side of a lush hill.

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

This elegant arc of a waterfall marks a religious turning point.

Iceland's "Smoky Valley" is a beautiful river that is shrouded in a constant cover of steam clouds.

Climb right into the heart of this colorful Iceland volcano.

An encyclopedic collection of mammal penises.

This fantastical waterfall is hidden in a cave located in a cracked cliff.

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

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

Got apples?

A mechanized clock where a man fights off a dragon, crab, and rooster.

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

An immersive projection art installation uses sound, scale, and light to take visitors inside classic works of art.

The narrowest street in Paris.

Original cabaret handbills, posters, and feline artwork are a purrfect highlight of the Museum of Montmartre.

This Parisian fountain is a little bit fantasy and a little bit nightclub.

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

Medieval museum built over Roman baths that features famous tapestries of a lady and a unicorn.

This statue was given to France by the United States to commemorate the centennial of the French Revolution.

A surrealist timepiece by the artist of melting clocks.

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

A favorite Paris bar for U.S. expats, including Gershwin, Hemingway, and James Bond.