Manhattan's deadly West Side railroad, which killed hundreds of New Yorkers, is remembered by this simple plaque.

Twenty-three trees, each paired with a basalt stone, line a street in Chelsea, continuing an urban project started by German Fluxus artist Joseph Beuys.

Elevated freight railway turned wildly successful urban park.

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

In its day this historic fort held 100 cannons pointed in almost every direction to protect New York.

Lie in a hammock where George Washington stood.

The site of a fallen tree that protected Americans from British forces during the American Revolution.

The mass grave of a heroic Revolutionary War regiment sits below an empty lot near the Gowanus Canal.

The one-stop shop for all of your superhero (or evil arch-nemesis) needs.

Volunteer-run library dedicated to exploring five decades of activism history.

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

The only known Futuro house in North Carolina sits along a stretch of desolate highway on the Outer Banks.  .

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

A hidden architectural treasure in New York's Brooklyn.

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

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

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

You can still ride this 100-year-old work of art in Brooklyn's largest public park.

Sniff the Titan Arum's rotting flesh.

This secluded ruin was once a home for exotic plants.

This metal eagle one of the final remnants of a newspaper that wanted to keep Brooklyn to Brooklyn.