Long-abandoned trolley tunnels just a mile away from the White House are turning into an art space.

Every drop of D.C. tap water flows through this old waterworks.

The hidden ruins of a mill that is linked to an attempt to assassinate the vice president of the United States.

Tombstones and enigmatic inscriptions hide within a vault beneath a popular London arts venue.

The anatomical-pathological collection of a man who changed surgery.

One part local history, 99 parts gruesome haunted house.

The perfectly preserved underground rooms where Churchill plotted the war against Germany.

The legacy of a wealthy executive and his wife, this little-known art museum features works by Picasso, Monet, Renoir, Cezanne, and more.

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

Franciscan monks created a facsimile of the Holy Land for North Americans who couldn’t afford the trip overseas.

This shop and gallery is a modern-day cabinet of curiosities, unassumingly positioned along an urban thoroughfare.