Huge masonic hall in Philadelphia with lavishly themed rooms.

This elaborate towering structure was once famed for its revolutionary height.

This simple convenience store sits on the location where the Ouija board was named—and has a plaque to prove it.

A monumental statue of RCA's mascot now sits atop a historical society roof after a life of moving around.

The design of this historic domed church was influenced by Thomas Jefferson and intended as a statement of religious freedom.

The site where Poe "in great distress, and ... in need of immediate assistance" likely died.

Once a thriving business district, this former shopping area is now an urban ghost town in the heart of the city.

The site of the climactic scene from the classic horror film is now a historic landmark.

This stately mansion, built in 1787 by America's first Secretary of the Navy, is rumored to be one of the most haunted buildings in Washington, DC.

At 207 feet, one of the world's longest continuous escalators.

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

This church built atop a gas station promises to "equip you for the next stage in your life’s journey."

This unique historical monument features large concrete spheres designed to resemble fallen stars.

There’s a hidden military meme engraved on the World War II Memorial.

A derelict bit of infrastructure from the canal that once ran through D.C. is landlocked in the heart of the city.

The grand marble structure next to the White House is Andrew Carnegie's temple to Pan-American diplomacy.

This nine-story building is the oldest standing skyscraper in D.C.

Legend has it that President Grant’s frequent drinking in the lobby gave rise to the term “lobbyist.”

The 28,000-year-old specimen is remarkably intact.

Washington's iconic carousel has a nice piece of Civil Rights history.

D.C. once had its own tiny rival to the New York Stock Exchange.

This fertility idol of questionable authenticity inspired an iconic Indiana Jones artifact.

The Byzantine, pre-Columbian, and medieval art at this stately mansion are some of the most under-appreciated collections in D.C.

This unassuming passageway played a key role in one of the most important events in U.S. history.