The world's largest carnivore sanctuary is home to over 450 meat-eating rescues.

This Las Vegas casino boasts one of only three spiral escalators in the United States—an engineering wonder.

Dyed by iron oxide over centuries, these sandstone rocks rise thousands of feet into the sky.

These remote Florida islands have a history of sea turtles and sunken treasures, and one of the world’s largest coastal brick fortresses.

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

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

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

This recessed garden protects thousands of mountain plants by creating its own microclimates.

This demon atop the Notre-Dame de Paris looks utterly bored.

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

This modest marker near Notre Dame identifies the very center of Paris.

The narrowest street in Paris.

The tradition of open-air secondhand and antiquarian bookselling in Paris dates back to the Renaissance.

The celebrated eyesore created by starry-eyed sweethearts.

This surreal statue brings a famous French novel about a supernatural cad to arresting life.

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

Twelve grave-faced marble angels guard the emperor's tomb at Les Invalides.

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

Statues of a fire-breather, a clown, and a whole performing troupe celebrate Luxembourg's creative side.

An expansive complex of subterranean tunnels is all that remains of one of Europe's most formidable medieval fortresses.

An ancient Roman relief beautifully preserved on the façade of a house.

Explore this medieval cathedral by trying to spot all the malevolent monsters hiding in its beautifully colored windows.

There has been an astronomical clock on this spot since the 14th century.

A pink sandstone column once used in ancient times to measure one's belly after a night of debauchery.