The oldest stone house in Paris was built by its most famous alchemist.

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

A popular European tradition makes its way to the states on one of America's most famous bridges.

The mysterious empty cupola behind the monumental arch points to an ancient prophecy of Delhi.

135 bronze medallions mark a French meridian line which once rivaled the hotshot Greenwich timeline.

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

The very center of Paris is surrounded by a bevy of strange good luck rituals.

Inside a former cabaret, seven floors of erotic art.

The celebrated eyesore created by starry-eyed sweethearts.

This bridge was constructed from the rubble of the infamous Bastille.

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

Famously misunderstood wonder of the ancient world

This lovely, if imposing, piece of Canadian gothic is possibly the most photographed hotel in the world.

These Egyptian statues have survived for 3,400 years and were an acoustic wonder of the ancient world.

The remains of Martha, the last known passenger pigeon, serve as a tool to educate about conservation.

A traveling postal dog covered 48 states and more than 140,000 miles, and he lives on as taxidermy, patched up with a rabbit's foot and a pig's ear.

A haunting tribute to pioneering photographer Clover Adams.

The most decorated dog of World War I is preserved in the Smithsonian.

Home to items never before seen by the public.

This Industrial Age architectural and engineering gem helps visitors and residents alike traverse Lisbon, “The City of Seven Hills.”

A floating cat sanctuary on an Amsterdam canal.

An Amsterdam street lined with antique shops each one dedicated to a different obscure collection.

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

A cluttered and astounding collection of antiquities and curiosities.