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

The world's oldest continuously operating airport was founded by the Wright Brothers.

Surrounded by traditional homes, this Tolkien-esque dwelling stands out on a quiet street in suburban Maryland.

Electronic inventions that resulted in products and systems we use every day are on display in this labor-of-love museum.

A lawn full of retired spacecraft on display at one of NASA's first research labs.

The whole world in one water tank.

Built by the patriotic residents of Boonsboro in a single day.

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

George Washington's dentures and Queen Victoria's dental instruments are in the nation’s official museum of the dental profession.

The longest escalator in the Western Hemisphere takes over three minutes to ride down.

Once part of a dam servicing an early 19th century grist mill, the tucked-way falls are a tricky-to-find urban oasis.

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

This English-inspired Maryland garden is home to acres of opulent plant life including bushes shaped into an entire fox hunt.

A priceless collection of the Nation's cryptologic history.

It's not hard to see why the historic Peabody Conservatory of Music's library has been described as a "cathedral of books."

This free, take-a-book shop seems like a trick but isn't.

Eighteen miniature death-scene dioramas.

Memorial stone for GWAR vocalist, depicted in his iconic costume.

This giant 200-year-old ginkgo is one of the largest in the United States.

This local mascot has been a presence in the area since the 1960s.

Dedicated to a U.S. Army lieutenant colonel who was also a bird watcher and artist.

A sculpture made from recycled materials and hand-blown glass dedicated to transportation and transformation.

Every autumn, this grove of living fossils erupts in a blaze of brilliant golden-yellow leaves and stinky fruit.

Home to the organ played at General MacArthur's funeral.