This 25-foot tall clock tower commemorates the start of one of America's foremost shopping districts and the end of the historic Palm Beach Pier.

One of the world's oldest continually operating bookstores.

This huge, disused viaduct is now a crumbling concrete underworld of covered in years of graffiti.

An ideal wedding spot that is almost too ideal.

This small interfaith chapel lies not far from the rim of the Grand Canyon.

A master of trompe-l'oeil creates a stunning, tourist-fooling dome out of a flat ceiling.

What was once a true peninsula has now been filled in, causing the water to recede and leaving many streetside "waterfronts" and landlocked "islands."

A rock outcropping left by a glacier that made itself useful throughout the centuries.

A former sanitarium where soldiers were sent to recover in the healing waters of hot springs.

This geothermal hot spring hides beneath a slowly growing mineral dome.

Once the largest gravity dam in the world.

It's not a typo, now say it five times fast!

The largest body of water in Massachusetts annihilated four small towns just to slake Boston's thirst.

Mortarless walls that stretch for miles are a lovely solution for creating grazing land in the harsh terrain of the Aran Islands.

Certain traditions prevail on the least-visited island of the Aran Islands.

Infamous marsh filled with toxic waste, World War II-era London rubble, and dead mobsters galore.

In the past, Renaissance sex workers were encouraged to entice customers on this bridge.

This extraordinary Depression-era expenditure was modeled after a postcard of a Mediterranean hotel.

A vertically floating hemlock controls the waves and weather at Crater Lake.

This magnificent herd of stampeding elephants has been frozen in time for over a century.

Before it was buried by volcanic ash, this fast-food restaurant fed the hungry hordes of ancient Rome.

The fastest transatlantic ocean liner sat abandoned in a Philadelphia shipyard for decades.

One of the only Florida forts to remain in the hands of the Union all through the Civil War still stands as a historic stronghold.

The tomb of Increase Mather and his son Cotton, influential colonial ministers obsessed with the occult.