Medicinal spa created from the mineral-rich runoff of a geothermal power plant

One of the tallest buildings in Iceland, and perhaps, the most visually impressive.

The largest whale museum in Europe allows visitors to walk among life-size giants.

The real-life site of Ichabod Crane's infamous gourd attack.

Oldest existing church in New York and the inspiration for Washington Irving's "The Legend of Sleepy Hollow."

The world’s first penitentiary, meant to be humane, drove men insane.

America's most famous museum of medical oddities is home to the remains of Albert Einstein's brain.

This elaborate towering structure was once famed for its revolutionary height.

World War II bunker still standing on the New Jersey beach.

The rare American Civil War-era weapon was never fired in anger.

One of the most enjoyable bits of history at Coney Island and “the most romantic ride in the world.”

Once America's longest-manned military fort, now an abandoned hulk.

One-time largest man-made structure in the world will be a park in 30 years.

The final resting place of some of Staten Island's earliest settlers and their descendants.

Final resting place of two dozen New York City harbor ships.

During the American Revolution, this mansion hosted failed peace talks between the British and Americans.

This shallow cave got its name from copious amount of human bones found inside.

Island where motor vehicles are banned -- home to the only carless highway in the United States.

The granddaddy of all tourist traps, built on ice water, jackalopes, and a giant dinosaur.

One of America’s oldest and spookiest hotels, thanks to the residency of ghosts, dead presidents, and Alfred Hitchcock.

This replica stave church looks like a piece of Norway was simply plopped down in South Dakota.

A monument to the egos of two railroad magnates that fell into decline along with their careers.

Star garnets are so rare that you can only find them in two places on Earth—here, you can dig for them.

With its webbed walls and bright red coloring, Calgary's iconic bridge looks like a finger trap puzzle stretched across the river.