This palatial botanical garden is home to one of the largest pipe organs ever installed in a private residence, and a piece of Wood's cycad.

The fastest transatlantic ocean liner sat abandoned in a Philadelphia shipyard for decades.

The first American department store, and home to the largest operating musical instrument in the world.

The body of St. John Neumann and his collection of hundreds of relics, on display in a Philly church.

Golden and naked, the figure that was once the highest point in New York is all that remains of the second Madison Square Garden.

This Philly cemetery is the eternal home of many famous area residents, including Rocky Balboa's wife.

Eccentric concrete mansion and museum designed and built by hand from the inside out.

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

A tiny piece of the Moon is embedded in this stained glass masterpiece.

The sci-fi villain is a little-known inhabitant of the U.S. capital's largest cathedral.

The only Civil War battle in Washington D.C. took place near this highest natural point in the city.

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

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

Light bulbs, scrap wood, and tinfoil comprise this homemade throne of the gods.

The house where John Wilkes Booth conspired with his co-conspirators.

Largest Roman Catholic church in North America.

Art deco landmark on the outskirts of Washington, D.C.

The Corinthian columns that towered over Abraham Lincoln’s inauguration stand proud.

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