The story behind the mysterious symbol painted in front of the historic university's famous Rotunda.

Outdoor exhibits explore the contributions of European, African, and indigenous peoples to American frontier culture.

A former mental hospital founded in the 1930s by a eugenicist who advocated for the forced sterilization of patients.

Go take a picture with the inventor of the daguerreotype photographic process.

This elaborate towering structure was once famed for its revolutionary height.

Crammed into a Baltimore row house is an oddities shop that sells everything from skulls to dead insects.

The trials and tribulations of marking Poe's grave.

World's first "penitentiary," meant to be humane, drove men insane.

This charming colonial alleyway is one of the oldest continuously used residential streets in the U.S.

The final resting place of two (or three) presidents, one vampire, and 18,000 Confederate soldiers.

This unique museum cafeteria showcases the history and regional diversity of African American cuisine.

A little marble compass above George Washington's (empty) tomb in the Capitol marks where D.C.'s four quadrants intersect.

Rumor has it the uncarved lump behind the three famous suffragists is reserved for the first woman president.

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

One critic described it as "middle Mussolini, early Ramses, and late Neiman-Marcus." Another called it an architectural "natural disaster."

"Congress may voluntarily remain in session throughout the summer, in order that our Congressmen may be protected from the intolerable discomforts and dangers of the ordinary outdoor weather!”

Members of Congress have traveled between the buildings on Capitol Hill for a century hidden from tourists, press, and storm clouds.

The tallest The Church of Jesus Christ of Latter-day Saints temple in the world soars above the Beltway.

Regency-era excess on the English Coast.

Cherokee alphabet, proof of ancient North American Jews, or just a hoax?

The 5.5-mile ring of steel posts around the Capitol Building is one of the largest (and most uniform) of its kind in the world.

Must form and function forever remain at odds? Not if the Florida Department of Transportation has its way.

Step back in time on this preserved 1800s farm.

This road in the Great Smoky Mountains was supposed to assuage a displaced community, but ended up a $52 million dead end.