This New Orleans tree is filled with hidden chimes that produce a carefully tuned melody.

Once the world's largest reinforced concrete structure, this abandoned bridge now beckons urban explorers.

Frank Lloyd Wright's most iconic home dangles over a Pennsylvania waterfall.

A toxic ghost town sitting atop a massive coal fire.

This secluded ruin was once a home for exotic plants.

The remains of what was once the world's steepest passenger funicular.

A crumbling hospital from the 1850s on Roosevelt Island.

Final resting place for the Triangle Shirtwaist fire’s unidentified victims.

A mysterious air force base built to resemble a Long Island fishing village.

Once a flowing stream and where the USS Monitor, the world's first ironclad, was built and launched.

A burial ground of rusting metal grave markers.

This huge, disused viaduct is now a crumbling concrete underworld of covered in years of graffiti.

The origins of midtown Manhattan's anachronistic wooden farmhouse remain a mystery.

A Red Hook dive bar that is holding onto its roots.

Ride the subways of yesteryear.

Read a book next to a Midtown waterfall.

An abandoned horticulture institute gloomily presides over rows of derelict and vine-wrought greenhouses.

First a horse rendering plant, then a 19th century landfill, this beach is full of glass from thousands upon thousands of broken bottles.

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

From scholastic to sepulchral - now under reconstruction.

America's first public mental health facility.

A scenic fort on the harbor protected Philadelphia from an attack that never came.

A tunnel once abandoned now thrives with graffiti art as an off-limits makeshift gallery.

Abandoned power station once home to a squatter community, now being developed into an arts center.