The original vault that held the president's remains still stands, empty, not far from where he was finally buried.

Abraham Lincoln's likeness rests at the top of this giant totem pole.

A 30-year-old Sycamore tree grown from a seed taken to the moon and back.

Thousands of tiny squares in different colors make up this piece of street art.

This tiny man looms large over downtown Charleston.

What is it about mushrooms that makes people wish they lived inside of them?

You can walk through the first Boeing Air Force One, which famously carried JFK's casket from Dallas back to D.C.

A real flying saucer, contracted by the U.S. Air Force.

The headquarters of the famous Yale society.

While many places make the claim, the Library of Congress says this restaurant is the birthplace of the hamburger.

A historic arena where the Beatles played their first concert in the U.S.

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

A Spiritualist house of worship where believers communicate with the dead in the spirit world.

A historic estate packed with George Washington's heirlooms, and its own nuclear bunker.

Also known as the Founding Church of Scientology.

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

The famous abolitionist’s preserved estate is one of Washington's finest monuments to its great Black citizens.

A super-sized promotional trick that is now a D.C. landmark.

Largest Roman Catholic church in North America.

Giant acorn-shaped 19th century gazebo from which suburban Washingtonians gazed upon the original "silver" spring.

An allegorical sculpture in Maryland wears the artist’s politics on its trunk.

An easy-to-miss plaque marks the building that first held this 19th-century telephone innovation.

An iconic steel and chrome diner from the 1940s left empty for nearly 20 years is in danger of being demolished.

The former home of Samuel Clemens and family remembers the happiest period of the author's life.