Inspired by a foil-wrapped potato, (seriously) the Markel Building has been deemed one of the 10 ugliest buildings in the world.

The semi-reclaimed ruins of this canal were once part of an ambitious plan to reroute the mighty potomac.

An alternate history park where the Union Army loses the war... to dinosaurs.

Bubbling up from deep underground is the warm crystal clear water that fills the Warm Springs Pools, America's oldest spa.

At 207 feet, one of the world's longest continuous escalators.

This 29-ton granite ball spins around at the slightest touch thanks to a scientific phenomenon.

Heron, whitewater rapids, and urban industrialism all add to the beauty of this concrete nature walk.

A railroad tunnel that, upon its completion, was considered one of the engineering marvels of the modern world.

Outsider art meets paleontology at this roadside reptile repository.

An organ located deep within a cave, whose "pipes" are the geological features of the cave itself.

A 300-yard long natural tunnel runs through a ridge deep in the Appalachian Mountains.

A sacred site for Native Americans surveyed by George Washington and owned by both King George III and Thomas Jefferson.

A mysterious echo seems to defy the laws of acoustics.

Once home to seven different roller coasters, Glen Echo has undergone many transformations since its founding in 1891.

A secretive collection featuring objects that were designed specifically for U.S. intelligence operations.

Three prestigious academic collections come together to create a world-class natural history museum.

A historic bridge with a lovely acoustic anomaly.

This abandoned lighthouse looks like a rusting oil rig, but has managed to survive a number of storms.

The Burnside Fountain and its questionable interpretation.

Ironically this massive termite is the mascot for a company that is acclaimed for killing his kind.

Reforestation in action is the main attraction in this abandoned quarry.

These World War I shooting range tunnels are now haunted halls of underground graffiti accessed through the roots of a tree.

Six peaceful acres in a residential neighborhood dedicated to art and peace.

Feral cats keeping the rodent population at bay all across Greenpoint waterfront.