Four bald cypress trees in Lafayette Square, across from the White House, mark the southern edge of a 100,000 year old cypress swamp.

A historic estate packed with George Washington's heirlooms, and its own nuclear bunker.

This leafy estate is worth $18 million and is so grand it has two mailing addresses.

A lovely aquatic park built by a one-armed Civil War veteran who made a fortune from lotuses.

A historic neighborhood church is reborn as a psychedelic arts collective.

During the Industrial Revolution this “Temple of Invention” was full of intricate miniature machines and gadgets.

A hidden gem on the lawn of the U.S. Capitol Building designed by landscape architect Frederick Law Olmsted.

A wondrous old library overlooking the nation's capital.

There's a 12-foot-tall replica of the Washington Monument hidden under a manhole nearby.

Enormous piles of historically significant stones, dumped by Congress in a forest, and abandoned for 60 years.

Home to items never before seen by the public.

With over 100 jam-packed rooms to explore plus elaborate tea services and events, the Mansion on O Street is a hidden treasure.

Labor provided by Great Depression-era programs restored these 25,000 acres in Tennessee.

A cement mixer-turned-kaleidoscope in downtown Norfolk offers different views of the city.

One street divides a single town that stands in two U.S. states.

The highest point in Virginia can only be reached by passing through ponies and flowers.

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

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

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

Visit this playground of waterfalls, caves and sinkholes.