A mysterious artist-run cabinet of curiosities and library.

Since 1874, this macabre collection has developed into a museum devoted to Scotland Yard's mementos of dastardly deeds.

English antique dealers with a taste for the unusual.

A historic London pub with prison cells in the cellar and a "spy room" on the second floor.

A tiny replica of the iconic London landmark hides on the side of the steel structure.

Standing for over 200 years, the abandoned home of a Revolutionary War hero and later a succession of prison superintendents.

This twice-relocated "Usonian" home is among the smallest built by master architect Frank Lloyd Wright.

Dedicated to a U.S. Army lieutenant colonel who was also a bird watcher and artist.

A mammoth pair of Civil War artillery guns abandoned out in the forest.

The first national memorial to honor all women suffragists stands on land where suffragists were once imprisoned.

The last of nine massive kilns that produced many of the red bricks for buildings in Washington, D.C. and northern Virginia in the early 20th century.

A memorial dedicated to a highly decorated Marine and Korean War veteran, who also happened to be a horse.

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

This methodist cemetery is slowly receding into the wilderness along a Maryland highway.

This ruined fort hidden at the top of Central Park can't seem to keep from losing its historical plaques.

Amid skyscrapers and traffic exists this unique aquatic ecosystem.

A tiny museum housed in a New York freight elevator specializes in the "overlooked, dismissed, or ignored."

Amid the bustle and noise of the Financial District hides a secluded garden oasis above the city streets.

Hordes of precariously balanced stone figures crowd the shores of the Hudson River.

Long the exclusive domain of birds and vagabonds, this little-known Central Park peninsula is open to the public once more.

This theater opened in 1998, but both the building and the puppeteers who perform there have a distinguished history.

Hidden in Central Park's Ramble is a troublesome cave buried just beneath the surface.

A New York garbage depot holds a secret collection of weird and wonderful refuse.

For over 30 years the walls of this Harlem schoolyard have been a gallery of street art by "Kings and better."