The massive, original Colgate Clock is mounted on a defunct factory building that was once a prison.

The chiseled jaw of this forgotten American hero still stands tall in a small Indiana town.

The lynching and burial site of America's first train robbers.

For over 100 years, this Indiana town has had a tree growing out the top of the local courthouse.

The world's largest anatomically accurate brain sculpture.

The only freestanding table rock formation east of the Mississippi.

Once adorning a New York skyscraper, these reclaimed ruins now haunt an Indiana park.

A largely forgotten and touching neoclassical marble fountain overlooking a bear mound effigy.

A bronze plaque marks the site of the only show the "King of the Soul Singers" ever missed.

The birthplace of a titan of American cinema.

This solitary gravestone is separated from the rest in Appleton, explaining why local legends continue to surround it.

Giant six-pack could provide one person a six-pack a day for 3,351 years.

The bugs crawling down the front of this office building are almost as big as a '68 VW Beetle.

Statue dedicated to the star of an old television show.

An overlooked oasis of quiet on the grounds of Washington's monumental basilica.

Every drop of D.C. tap water flows through this old waterworks.

The only National Monument ever to go missing for nearly 50 years then resurface in a dump.

A heroic pigeon that, through a barrage of gunfire, delivered a message that saved over 100 lives in World War I.

A computer bug so primitive it was an actual insect.

The walls of the iconic dome are hollow and have a secret stairway.

A cavernous three-story, 43,800-square-foot basement that was forgotten about for 60 years.

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

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

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.