These fantastically named natural pools look like something out of a Scottish myth.

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

Statue of death tucked in the University of Medicine courtyard.

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

This massive library holds what was once the largest book collection in the world.

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

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

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

This massive blockhead sculpture hides an entire library.

A medieval military street hidden beneath a charming French fishing village.

The sign at the garden gate reads: "These Plants Can Kill."

This ornate Victorian marketplace was the setting for Diagon Alley and the Leaky Cauldron in the Harry Potter films.

The world's largest and most outstanding marl lake regularly changes color.

Few other hotels can rival the grandeur of the Castle in the Rockies.

A grand Gothic Revival basilica with stained glass depictions of Montreal's religious history has only one soul resting in its crypt.

Fossils, railroads, and waterfalls!

Defying all odds, this lonely little tree found a home on a log sticking out of a Canadian lake.

Designed by Buckminster Fuller, this relic of the 67 Expo survived fire and ice.

This 1967 experiment in modular architecture was designed to be a new model for urban living.

Railways may have forged this quintet of lovely tunnels, but now they are open to hikers.

Sleep snuggled in a sphere suspended atop the forest canopy of Vancouver Island.

Although rarely used, there is still a hidden room for the royal family at the Stockholm central station.

An eclectic sculpture park rises atop a giant pile of ashes in Sweden.

A floating underwater hotel, created by a Swedish artist.