This unassuming passageway played a key role in one of the most important events in U.S. history.

A celebrity from the late Cretaceous period.

Home to a vast and influential collection of Shakespeareana.

When it opened during the final years of the embargo, all the drinks and cigars were free.

The country's oldest continually-operated mini golf course lies hidden in plain sight, eclipsed by one of D.C.'s most popular tourist attractions.

A three-story tower of books about Abraham Lincoln is one of the more unusual monuments to the president.

This lonely waterfront memorial to the men of the Titanic was erected by the "Women of America."

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

A hidden gem on the lawn of the U.S. Capitol Building designed by landscape architect Frederick Law Olmsted.

A wondrous old library overlooking the nation's capital.

Enormous piles of historically significant stones, dumped by Congress in a forest, and abandoned for 60 years.

A historic neighborhood church is reborn as a psychedelic arts collective.

This grand gothic brewery has been pumping out suds for over a hundred years.

One of the dwarven trees dates back to 1625 and survived the Hiroshima bombing.

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

The United States Capitol's former columns still stand.

A double agent hid information for the Soviet Union beneath this bridge for more than 20 years.

A graveyard that dates back over 200 years stands near a busy shopping center.

The most historic church in Fairfax County played a role in the creation of the American Red Cross.

A decaying garage hidden amid the dense forest is all that remains of a once-prosperous dairy farm.

This Virginia railway overpass is said to be haunted by a serial killer in a rabbit costume.

Where pardoned turkeys once spent their all-too-brief final days.

A lone historical marker off the highway and scattered debris are all that remain of this Cold War-era missile site.