Where now stands a 42-story condominium tower of marble, glass and steel was once the central market of New York’s slave trade.

Unrepaired walls from a 1920 anarchist bomb attack.

The iconic boulevard is the perfect place to catch sight of a bicycling skeleton, a levitating Satan, or a chef with his head stuck in a pizza.

Leaf through over 30,000 artists' sketchbooks in what may be the world's largest collection of doodles

This lower Manhattan bar is set up in an old bank vault that rests beneath a skyscraper that hides even more historic splendor.

This beautiful building in the heart of Manhattan's Financial District was empty for decades.

An odd, ancient window that may have once been part of a brutal prison is embedded in the side of New York's Police Plaza.

Visit the site of a subway powered by nothing more than air--and lots of it.

Sniff the Titan Arum's rotting flesh.

Ride the subways of yesteryear.

During the holidays, a vintage subway train whisks New Yorkers back in time.

A hidden "place of interment for gentlemen."

The artist and New York City icon lived, worked and died in this converted carriage house owned by another iconic artist, Andy Warhol.

These historic buildings once housed the headquarters of one of the most infamous gangs of New York.

A terrific purveyor of natural history objects and curios.

This wall on a street corner in Lower Manhattan has been a blank canvas for a rotation of renowned artists since the 1980s.

This modest post office sits on the site of H.H. Holmes' famous murder castle.

The only way to see Pittsburgh is from the top of this lookout point, just like the ancient members of the native peoples did.

There aren't too many operational funiculars around, but Pittsburgh has two!

Meet your friends, marry your true love, or tell your enemies to kiss your butt under this historic Pittsburgh timepiece.

A restored Pittsburgh house of God has been converted to a marvelous house of suds.

This church in Pittsburgh is home to the largest collection of religious relics in North America.

Found art has transformed this Pittsburgh neighborhood into a psychedelic dream.

The clothes-washing king doubles as a community center with some unusual features, including an aviary filled with finches.