This mysterious structure by the Washington Monument is a flood barrier designed to protect the White House against rising waters.

An overlooked memorial honoring the local Washington residents who died in World War I.

This tiny home built on revenge appears to be scarcely wider than a Volkswagen.

Spanning an elevation of 160 feet and containing 388 steps, this is Seattle's longest staircase.

A tiny plaque hidden miles into the Washington wilderness is all that remains to honor a shipwreck that left 18 people dead.

A surreal landscape where fanged rocks rise from the ground and the ocean feels like a great mystery.

Berthed at the Charlestown Navy Yard in Boston, "Old Ironsides" is the oldest commissioned warship still afloat.

This stoic, if derpy, giant stands as a monument to Oregon's statehood and the novelty culture of yesteryear.

These old stone ruins in the Oregon wilderness were once bathrooms and are steeped in legends of murder.

A heavenly experience, right here on Terra Firma.

At this Minnesota state park you can easily wade across the source of the mighty Mississippi.

The oddly shaped, steam-spewing building is now an art studio and gallery.

The hide of Stonewall Jackson's equine sidekick is on display not far from where the ashes of his bones are buried.

This humble star-gazing center touts itself as the "Birthplace of American Astronomy."

A real flying saucer, contracted by the U.S. Air Force.

This magnificent Cincinnati graveyard is also a popular public park.

Small, privately owned island divided between Michigan and Ohio with abandoned vacation homes and a derelict lighthouse.

This collection of Japanese luck idols beckons visitors with over 2,000 waving paws.

What is it about mushrooms that makes people wish they lived inside of them?

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

A "sinister, whimsical, tacky, and really orange" public art installation hidden under a Seattle bridge.

Hollywood's most famous landmark, the "temporary" sign that has stood for decades longer than intended.

A beautiful 62-acre Catholic shrine and botanical garden.

Now famous as the "Harry Potter bridge," this impressive concrete viaduct has long been an icon in its own right.