An abandoned railroad tunnel is now filled with bioluminescent bugs.

Canada's oldest railway tunnel is illuminated in a rainbow of color as it passes under the streets of this small city.

A fantastic array of trays and cables once whisked books over to the Capitol at 600 feet per minute.

Light bulbs, scrap wood, and tinfoil comprise this homemade throne of the gods.

Home to a vast and influential collection of Shakespeareana.

An Industrial Revolution-era public work that purified water using nothing but sand.

This stunning blue and gold room changed cities twice before becoming part of the Smithsonian.

A three-story tower of books about Abraham Lincoln is one of the more unusual monuments to the president.

A Spiritualist house of worship where believers communicate with the dead in the spirit world.

A historic estate packed with George Washington's heirlooms, and its own nuclear bunker.

A lovely aquatic park built by a one-armed Civil War veteran who made a fortune from lotuses.

Franciscan monks created a facsimile of the Holy Land for North Americans who couldn’t afford the trip overseas.

The Byzantine, pre-Columbian, and medieval art at this stately mansion are some of the most under-appreciated collections in D.C.

Long-abandoned trolley tunnels just a mile away from the White House are turning into an art space.

Home to items never before seen by the public.

Long before air conditioning, Persian architects found an ingenious way to cool off.

This 16th-century mosque is the hallmark of the African architectural legacy in India.

Fonts are born and bred here at the oldest letterpress type foundry in the United States.

Odd outsider art installations surround a Gold Rush-era ghost town.

A deserted hodgepodge of experimental structures designed by nearby university students.

The remains of a failed attempt at medieval nerdery are hidden deep in the woods of Virginia.

The abandoned "Ghost Mansion" was left to decay in the mountains of Northern Italy.

Shipwrecks, ruins, and turtles are all that remain on this haunting Caribbean ghost island.

An abandoned outdoor movie theater in the Sinai desert.