After Sierra Leone's railways shut down in 1974, a collection of engines and other artifacts spent decades hidden away in this old workshop—now a museum.

A glimpse into the sacrifices of military members during World War II.

This collection of over 50 classic pinball machines awaits visitors to downtown Roanoke.

This museum celebrates a legendary railroad photographer whose personal life was as dramatic as his photos.

A 19th-century architectural wonder designed by the "father of the skyscraper."

The only boathouse Frank Lloyd Wright ever designed was also the only unbuilt structure in his famous Wasmuth Portfolio, until 2007.

The seat of Buffalo government is a gorgeous Art Deco palace.

Original factory of John G. Borden who started what we know today known as Borden Dairy.

Hidden behind an industrial area, this is one of the very few such transporter bridges in existence.

Underground attraction offering tours of the foundational ruins of a church nave that collapsed in 1674.

Home to the world's oldest functioning orrery.

This functional solar system model was inspired by the famous Eisinga Planetarium.

A New England curiosity cabinet, one hundred years on.

One extremely determined man's homemade universe.

This state-of-the-art planetarium takes architectural inspiration from the sun itself.

A ghost town that was wiped out by a flood in 1940.

A perfectly preserved small-town pharmacy and soda fountain that opened in the early 20th century and closed in the 1980s.

Constant erosion has created a surreal landscape of bleached and preserved fallen trees.

Rusting, graffiti-covered tanks litter the beach of this island, once used by the U.S. military for target practice.

Hidden underground, a remarkable 10th-century bath complex survives virtually unaltered.

Two gushing waterfalls of hot spring water within a block of each other.

A gothic palace of endless stalagmites and pseudoscorpions waits within one of the world's most beautiful caves.

This famous Nevada gold mine, once a hotbed of Wild West shenanigans, is now open for tours.

Mine your own precious stones.