Former self-sufficient mental institution now a planned community.

A subterranean world of tunnels links several buildings of this rare 19th-century asylum.

This tree was warped centuries ago to serve as a botanical wayfaring tool.

A charming remnant of 19th-century fishing towns sits on Michigan’s Leelanau Peninsula.

Legs Inn provides Polish food, a cornucopia of Native American artwork, wood carvings, and mounted deer heads.

Macabre astrological automaton clock dating to the late 1400s.

After decades of research and rumors, Little Zion Church was proven to be his final resting place.

The unique traffic pattern named for an influential urban planner is also known as the Pedestrian Scramble.

This sandwich shop has a century-old elevator behind a sheet of plexiglass.

The privately owned cemetery that holds room for Washington's finest when they step down from life.

These recently uncovered walls are all that's left of Washington, D.C's first defense contractor.

Cold War intelligence agents monitored communist embassies from an attic in a former pigeon coop.

The famous abolitionist’s preserved estate is one of Washington's finest monuments to its great Black citizens.

The oldest continuously operating fish market in the United States.

The actual model from the original "Star Trek" series is now on display at the National Air and Space Museum.

People escaping slavery may have hidden inside a corpse vault.

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

The country's oldest continually-operated mini golf course lies hidden in plain sight, eclipsed by one of D.C.'s most popular tourist attractions.

This lonely waterfront memorial to the men of the Titanic was erected by the "Women of America."

The winding route passes through an enclosed alleyway, two tunnels, and leads to the White House basement.

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

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

A painfully obvious spy house sits right across the street from the Russian Embassy.

A monument in Washington D.C. marks the spot from which all other roads were supposed to stem.