Once the future of underwater combat, this old sub is now open for visitors to muck around in.

At this bayside marina, enormous wild tarpon jump out of the water to snatch fish from visitors’ hands.

The world's brightest bioluminescent bay.

On this Puerto Rican island, many abandoned naval ammunition bunkers sit open while a few have been padlocked by locals as personal storage.

The world’s second-largest flood defense barrier has protected London for decades.

The empty town of Scenic, South Dakota, is owned by a church in the Philippines.

A former waterfront market is now in the center of town due to some interesting Boston engineering.

The massive machine creates cracking displays of indoor lightning.

In 1958, an MIT fraternity pledge laid down on this bridge and instituted a new, unique unit of measurement.

The oldest covered railroad bridge still standing in the United States.

Delve into the life of Edna St. Vincent Millay, harbor town history, and a quiet seaside garden at this charming library.

This boat represents the promise of undiscovered territory, a dream of hope, and progress and freedom for Iceland.

For more than half a century, an enormous feline has watched over this London neighborhood.

The first transatlantic wireless communication between the U.S. and Europe took place here in 1903.

This historic hotel was once home to Henry David Thoreau and rumored to be haunted by ghosts of fallen soldiers from the American Revolution.

This sprawling, Brutalist estate feels like a city within a city.

Visit Europe's largest subterranean waterfall, carved by water from the glaciers of the towering peaks surrounding the valley.

One of London's lost rivers runs through a pipe over the tracks of this subway station.

With a history stretching back to the 16th century, this pub has a few stories to tell.

This unusually-named reservoir found a second life as a nature preserve.

Legend says these colorful, invasive residents are the descendants of birds released by Jimi Hendrix.

A community of artists and entrepreneurs seeks a simpler life on London's waterways.

Scattered throughout London are ancient remnants of the city's former bounding wall.

The famous author's cottage hideaway.