The only Bahá'í house of worship in North America and one of only a handful worldwide.

This legendary urban waterfall creates a dazzling display of rainbows.

A piece of the iconic wall found an unlikely new home in a Vegas bathroom.

This beautiful park on the outskirts of Rome protects the ruins of two colossal ancient aqueducts.

A century and a half of research in the sciences and natural history, still going strong.

A science teacher's dream.

The tea room that pushed the boundaries of adorable straight into... we can't find the words.

A collection of 20th-century automata, penny arcade games, and musical contraptions.

Join the circus for a few lessons to learn clowning, acrobatics, and Chinese contortion.

The last remaining relic of San Francisco's glittering 1915 Panama Pacific Exposition.

A winding path built in secret on the edge of the continent.

The gorgeous entrances into the city's underbelly look more like grand halls than subway stops.

This alley in downtown Chicago held the bodies of over 600 people after the fateful Iroquois Theatre fire.

A labyrinth of ancient tunnels hidden below the city holds the ruins of 2,500 years of history.

This $3 million model train takes you through Chicago, Seattle, and the thousands of miles in between.

One of the largest free-standing structures ever built, this dirigible hangar is now simply a giant skeleton.

The garage at the childhood home of Steve Jobs was a hangout for the founders of Apple, even if they never built computers there.

After the attack on Pearl Harbor, rocks and fossils from every U.S. state were collected into a pyramid of national unity.

Moscow's other, lesser known kremlin is a fairytale-like cultural complex modeled after Old Russia.

This remote island in Iowa was abandoned after being devastated by flood.

Each of these gorgeous, intricately decorated rooms is painstakingly crafted to the scale of 1 inch: 1 foot.

A display of magnificent stained glass windows is the first exhibit of its kind.

This botanical garden outside Chicago boasts an array of more than 300 varieties of lilacs.

Even with only two residents and one building, this tiny Illinois town is famous for its burgers.