This stately building in Alexandria, Virginia was built by Freemasons to honor one of their most famous members.

Once forgotten and built over, this historic Black cemetery now houses a poignant memorial.

This grave marks the passing of a historic Jane Doe whose identity remains a mystery to this day.

A former major munitions plant that has been converted into a sprawling art space.

This colonial tavern played host to George Washington, Thomas Jefferson, and other famous early Americans.

The final resting place of an unidentified revolutionary soldier sits behind a Virginia church.

This brick-lined pedestrian walkway was once a railway tunnel used during the Civil War.

This ghost town houses the remains of Alabama's old state capital.

Architecture lovers won’t stop touching the National Gallery's 19.5 degree marble prow.

Franciscan monks created a facsimile of the Holy Land for North Americans who couldn’t afford the trip overseas.

The stone marker that Mason and Dixon placed at the eastern end of the famous north-south border they surveyed.

A little marble compass above George Washington's (empty) tomb in the Capitol marks where D.C.'s four quadrants intersect.

The oldest building in the District of Columbia was preserved because of a mistaken connection to George Washington.

The narrowest house in America is seven feet of pure spite.

All of the 20 occupied houses in this mostly abandoned town feature some curious display of junk art.

A spiritual vortex among the red rocks in Sedona.

This immigrant bridge once spanned the Thames but is now a fixture of an Arizona city.

What is the Thing?

In a 345-million-year-old cave that's 200 feet underground, dinner awaits.

One of the largest, oldest, darkest, quietest motel rooms in the world.

An homage to everyone's favorite prehistoric cartoon family.

This 4,000-foot-diameter hole is touted as "the most well known, best preserved meteorite crater on Earth."

A land of debatable treasure.

An 1870s ranch for pioneers, rodeo stars, and divorcees was abandoned and left for dead, until the city reopened it for exploration.