Ride the subways of yesteryear.

A dilapidated dock tells the story of Titanic's missed arrival.

Hidden in Central Park's Ramble is a troublesome cave buried just beneath the surface.

The feral felines of Roosevelt Island have a small army of allies and an abandoned hospital all to themselves.

Elevated freight railway turned wildly successful urban park.

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

Try not to get slimed in Tribeca.

Manhattan’s Battery Park has a whimsical carousel full of spinning, glowing fish.

A crumbling hospital from the 1850s on Roosevelt Island.

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

One of the last remaining movie theatres in the country that features a rear-projection system.

The statue of John Harvard isn't actually John Harvard—or even, technically, the founder of the school.

This cemetery served as the only official burial grounds in Cambridge for nearly 200 years.

This tiny, painted door at the base of a tree stump has been a fixture of the Harvard University campus for decades.

This statue intended for children to enjoy became a minor political spat.

This headstone marks the grave of an 11-year-old boy killed during clashes in the streets over the boycotting of British goods.

Macabre headstones carved with winged skulls, dancing skeletons, and pithy reminders of impending death.

The site where Charles Dickens gave his first public reading of "A Christmas Carol" in the US.

The former locus of Boston's high culture has been shuttered and buried for over 70 years.

The site of one of the strangest disasters in history—a wave of deadly molasses traveling at 35 mph.