This groundbreaking 16th-century map is known as "America's birth certificate."

A throwback to 1980's gaming nostalgia.

This one-room doctor's office has been moved twice, and now lives on as a museum.

The location where the famed author and abolitionist began his journey to freedom.

The shelves in the back of this thrift store are devoted to saving, not selling, retro tech.

The site of one of the deadliest skirmishes during the Battle of Fredricksburg.

A historic Maryland home that once belonged to a man who has been called "the most insignificant" U.S. Supreme Court justice.

The first blast furnace in the United States that used coal and coke fuel instead of charcoal to make pig iron.

A coal town pitcher who became a record-setting legend, then came home to serve

Despite violent work crews and massive delays this abandoned canal tunnel was built to last into the modern day.

This one-room cabin where the young colonel slept during the French and Indian War.

Maryland's first (and last standing) toll house on America's first federal road established the state as the "Gateway to the West."

The antique hotel still has a jail in the basement, though the cockfighting ring is long gone.

This beautiful stone arch bridge wasn't even expected to stand for one day, but people have been crossing it for centuries.

A remarkable time capsule of American manufacturing deep in Maryland coal country.

The highest point in Maryland is only accessible by hiking through another state.

This claimant to the title of "smallest church in the 48 states" doubles as an equally tiny, quasi-post office.

This hollow steel globe is the second-largest in the world.

A street in front of NASA's D.C. headquarters has been named in honor of the Black women who were essential to early spaceflight.

An oft-overlooked, magically musical monolith that stands majestically between Arlington Cemetery and the Iwo Jima Memorial.

This lovely pocket park is one of the most under appreciated in D.C.

This Masonic lodge was the first major private building to be constructed in Washington, D.C. after the Civil War.

This nondescript row house in downtown Washington, D.C., was the home of a very secretive group for well over a century

A nostalgic bibliographic gem.