A 16th-century fountain marks the site of a lost medieval cemetery once filled with mass graves.

Notorious artist squat renovated into legal studios.

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

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

The Sun King's military models, saved from the Louvre.

The ruins of a Duke's bucolic dream, where camels once roamed alongside "Dutch" windmills and faux-Italian vineyards.

High atop the Eiffel Tower is a small apartment built exclusively to entertain the science elite and make the rest of Paris jealous.

An Orthodox church built by the Royal Family for the Russian community exiled to the French Riviera.

This statue of the great Argentinian car driver is located near a famous curve of the Monaco Grand Prix.

Museum celebrating the ocean, with the largest wunderkammer dedicated to sea exploration.

This public amphitheater was once a key part of Monaco’s defense strategy.

This massive blockhead sculpture hides an entire library.

The construction of a tram line unveiled hidden remnants of the old medieval city.

A memorial to honor those who were killed in a Bastille Day terror attack in Nice.

Knoxville’s architectural icon was the symbol of the 1982 World’s Fair, even catching the googly eye of Bart Simpson.

Wild lights and sound effects turn a walk through some caves into an eye-popping 1960s tourist attraction.

A visionary oral narration project brought new life to Jonesborough.

The longest-serving U.S. Secretary of State and Nobel Peace Prize winner was born in this humble cabin.

The pan man stands as a testament to the functionality of American cast iron cookware.

This large cave is a summer home to thousands of bats and has a rich history dating back to prehistoric times.

A bizarre roadside attraction and the first instance of miniature golf in the world.

This funicular railway rumbles along for a mile up the nearly vertical face of Chattanooga’s Lookout Mountain.

The mysterious wonder of an underground waterfall is illuminated by multicolored lights.

This museum dedicated to an oft-overlooked support industry features a surprisingly moving brass diorama of a man being saved from a sinking car.