Historic Greenpoint theater, turned roller disco, now housing a chain pharmacy store.

A hidden "place of interment for gentlemen."

The world's largest kaleidoscope, designed by a 1960s psychedelic artist.

A whimsical monument deep in this park commemorates the groups that helped build it.

The end of the 4 Line is also the end of the line for 300,000 souls in one of NYC's most illustrious cemeteries.

Detailed facade of a brownstone in Boerum Hill.

Ride the subways of yesteryear.

This sculpture by artist Fritz Keonig survived the 9/11 attacks and now stands as a monument to the victims.

This innocent-looking townhome is actually a subway exit.

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

Try not to get slimed in Tribeca.

Elevated freight railway turned wildly successful urban park.

The most confusing clock in New York.

An artist's cute bronze subway sculptures belie his violent artistic past.

A drawbridge named for a potentially intersex Polish national who fought alongside George Washington during the American Revolution, and an example of "Pulaski Red".

A graffiti Mecca welcoming artists from around the world.