Eccentric concrete mansion and museum designed and built by hand from the inside out.

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

One artist's love letter to his city and its citizens plays out across dozens of bright murals painted on the sides of decrepit buildings.

This little-known collection holds everything from "Dracula" notes, to the manuscript of "Ulysses," to the forged works of Shakespeare.

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

Huge masonic hall in Philadelphia with lavishly themed rooms.

Philadelphia boasts one of the best — and most often overlooked — traditional Japanese gardens in North America.

A rare view of a preserved Victorian science museum.

A layered tribute to the work of mosaicist Isaiah Zagar.

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

The only surviving sidewalk clock in Brooklyn.

A heartbreaking monument showing the last morning in the life of Jane Griffith.

A way to take your secrets to someone else's grave.

A burial ground of rusting metal grave markers.

A Brooklyn exhibit all about Nancy Kerrigan and Tonya Harding in 1994.

The world's largest collection of materials relating to lesbian history is housed in a Brooklyn townhouse.

Two community gardens under the elevated subway lines on a very busy commercial strip in Bushwick.

A tree that grows parallel to the ground was declared Brooklyn's "crowning curio" by the poet who saved it.

Thriving meadows span a rooftop in one of Brooklyn's most heavily industrialized neighborhoods.

A working metal shop and venue for outrageous art and music shows in a former cannonball factory.

This outdoor gallery of graffiti-covered walls pays homage to the past, present, and possible future of street art.

Check out the underground party scene at the "Burning Man of Brooklyn."

A Victorian cemetery in the heart of Brooklyn remains a popular mecca of morbid curiosity.

Come for the sustainable organic chocolate, stay for the sustainable organic booze.