The haunting, dilapidated remains of a former poorhouse on Staten Island's Greenbelt.

This abandoned seaside fortress is now simply an imposing ruin being taken back by nature.

Read between the lines of the subway map to find the hidden abandoned Civil War fort.

Four cars from the old system were once on display, but were removed in 2014.

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

Empty, but not abandoned, this cavernous Brooklyn loading dock was once considered the largest individual building in the world.

An abandoned subway tunnel that could have reinvigorated Staten Island still lies somewhere beneath this Brooklyn park.

Brooklyn's Barkaloo Cemetery is the resting place of a scant two bodies.

Once the supplier for noteworthy projects like the National Cathedral, this old brickworks now lies abandoned.

Once in a state of dilapidation, this candy-inspired fortress is now being revived.