Parking garage where Bob Woodward met Watergate source "Deep Throat."

Outdoor exhibits explore the contributions of European, African, and indigenous peoples to American frontier culture.

This tree is a living witness to the beginning of the Civil Rights Movement.

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

Conveniently located within binocular range of a nuclear bunker, the "summer camp" area was a painfully obvious spy house.

This museum sits on the site of a decommissioned military communications base.

The only recreation of William Shakespeare's indoor playhouse.

This pre-Revolutionary War grist mill ground corn and flour for soldiers in seven American wars.

One of the last active volcanoes on the Eastern seaboard.

This historic mansion was built as a symbol of love between a husband and wife.

This once-palatial plantation may have been the site where a draft of the Declaration of Independence was written.

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

This maze-like slot canyon is a unique gem within an already fascinating geological area.

Giant busts of 42 U.S. presidents are sitting in a field in Virginia.

The secret skeleton of a murdered nun was discovered in this church basement, but the scandal doesn't end there.

Famed for its pie, this eatery has a hidden tunnel that allowed Catholics to secretly walk to church during the Reformation.

This church houses the “incorrupt” body of its founding Bishop.