This was one of the first (and last) university-built and operated nuclear reactors.

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

This group of small islands on Lake Nicaragua formed after an eruption of the Mombacho volcano.

Abandoned 19th century homes once occupied by naval officers, soon to be demolished.

A huge resale shop for the cast-offs of the film & television industry.

This seemingly unremarkable boulder is said to bear the hoofprint of the devil himself.

Final resting place of the immigrant who brought artificial seltzer water to America.

A curious friendship between two inanimate ladies.

This recipe is set in stone.

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

A mass grave for victims of one of the city’s worst fires.

Records of the dead describe the myriad odd ways people used to die.

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

One of only two remaining Victorian-era greenhouses in New York.

A Collegiate Gothic quadrangle that surrounds an 18th century secondary school whose financing came from the likes of Alexander Hamilton and Aaron Burr, among others.

These century-old townhouses contain some of the first car garages built in the United States.

A mosaic made of materials gathered from this Brooklyn community adorns the walls of this tunnel.

This unusual subway stop was originally a real estate office.

A hidden architectural treasure in New York's Brooklyn.

This interactive gallery makes you feel like you've stepped into a fantasy world filled with whimsical monsters.

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

19th century cemetery hidden in Brooklyn's Prospect Park.

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

This elaborate tunnel is the first structure composed of cast concrete in the United States.