The Old Courthouse takes visitors on a captivating trip through St. Louis' timeline.

The only depiction of Abraham Lincoln holding a weapon, and the names of all 9,000 Cuyahoga veterans of the Civil War.

Cleveland's giant "free" stamp is a nod to the Civil War, but was misinterpreted for years.

This steamer is known as "The ship that built Cleveland."

Home to the largest urban bat colony in North America, estimated at 1.5 million bats.

An extraordinarily ornate museum in San Diego holds wondrous anthropological treasures.

Built for an exposition in 1915, these horticultural displays have stood the test of time.

A sculpture of the famous photograph stands on San Diego's "Greatest Generation Walk."

Deep into the lower floors of Pike Place, find a date with fowl fate.

The tech giant built three enormous glass orbs in Seattle so employees could work inside a rainforest greenhouse.

A unique underground structure dating back to the 1st century BC.

This ancient theater was once the home of fierce gladiatorial battles.

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

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

The video game-themed street art first popped up in the French city.

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

Stripes of human ashes cover a back lawn in the most sought-after burial grounds in Paris.

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

The celebrated eyesore created by starry-eyed sweethearts.

The approximate spot where the last Grand Master of the Knights Templar was put to death.

If you look closely at the oldest bridge in Paris, you might notice hundreds of ugly faces leering from its sides.

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

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

The water-powered carriages are long gone, but for over a century this funicular railway has been the fastest route to the highest point in Paris.