This mighty white oak in Bethesda survived both the American Revolution and the construction of Washington D.C.'s metro red line.

Built in 1945, this historic train station has a new lease on life with its baggage area serving as an event space.

These five Art Deco homes were meant to solve the "small house problem."

This bell is one of the last remnants of the lost city of Triadelphia.

This general store has stood in the same spot for well over a century.

Washed out by the Johnstown Flood in 1889, the surviving portion of the original two-span bridge now resides at Fishing Creek.

First built around 1848, this bridge was destroyed by arson, but original timbers are included in the replacement.

The smallest covered bridge in Maryland.

An astounding collection of medical specimens, including bits of President Lincoln.

One of the largest collections of Catalan literature and cultural materials outside of Spain, created by a community of 1960s expats.

Walk a trail through a historic Quaker town that outlawed slavery in 1777 and was a major waypoint on the Underground Railroad.

A suburban museum tells the story of a historic transportation network and even provides rides in antique trolley cars.

A labor of love built by local hang-gliding enthusiasts, this ideal launch spot was outlawed by the authorities and has since been largely abandoned.

The Cold War-era "underground Pentagon" is a sprawling subterranean hideaway for the Defense Department.

The tallest church in Mechelen might have been the tallest in the world if not for a lack of funds.

Right next to departures—how convenient!

The remains of a historic plantation nestled in between a parking lot and the rental car return at Reagan National Airport.

The only public swimming pool in Baltimore open to Black Americans during segregation is now a permanent memorial art exhibit.

A miniature city within a city, complete with traffic signs, signals, and streets to teach Baltimore's youth traffic safety laws.

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

A small 19th-century graveyard tucked away in the middle of a suburban neighborhood.

This lovely tree was a thank you gift from the man known as "Public Enemy No.1."

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

An abandoned church gets a second life as a massive beer hall and event space.