The one-stop shop for all of your superhero (or evil arch-nemesis) needs.

With over 100 jam-packed rooms to explore plus elaborate tea services and events, the Mansion on O Street is a hidden treasure.

Dodge prohibitionists and slide through the telephone booth in Crif Dogs.

The world's only museum devoted to the wonders of fluorescence.

Mysterious rocks that ring musically when struck.

Eighteen miniature death-scene dioramas.

A museum devoted to bringing to light forgotten or neglected histories through exhibitions, education and public programming.

La Monte Young and Marian Zazeela's "Dream House" will immerse you in an ever changing world of sound and light.

A terrific purveyor of natural history objects and curios.

Dr Barnes' $25 billion private collection of art and arboretum.

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

A beautiful and abandoned New York subway station from 1904, complete with chandelier.

America's most famous museum of medical oddities is home to the remains of Albert Einstein's brain.

A Civil War Museum with some notable medical antiques.

Bizarre Cavern.

The first purpose-built art gallery in the United States is once again open as a center of craft arts.

Four bald cypress trees in Lafayette Square, across from the White House, mark the southern edge of a 100,000 year old cypress swamp.

An easy to overlook storefront hides some of the most authentic and regionally diverse Chinese food in New York.

A legendary speakeasy bookstore returns from the brink.

This enormous Hindu temple in Queens serves incredible dosas in its basement canteen.

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