The abandoned ruins of America's first private zoo are open for exploration in the Catskills.

Clusters of abandoned buildings hint at the facility's 144-year history with psychiatric health.

Forgotten under the construction of a new urban roadway is a small, abandoned part of town.

An overgrown garden stands as a grim marker of an unrealized dream.

A mine fire has been burning under the deserted town since 1962, but this church is still going strong.

One-of-a-kind preserved ruins of an abandoned 1880s church in Chicago's Pilsen neighborhood.

These abandoned grain silos and tunnels are an urban exploration dream.

The ruins of an abandoned 18th-century town that is slowly being reclaimed by the forest.

Hundreds of numbered stakes hidden in the woods mark the graves of the lost souls of a nearby asylum.

A forsaken wonder in the middle of the East Side neighborhood.

Locals dubbed this abandoned abode the "gingerbread house" because of its odd architecture.

A hidden piece of Altoona's railroad history in a long-forgotten abandoned town.

This dam in the woods, built by Henry Ford with only manpower and oxen, holds no water and serves no purpose.

This abandoned bridge to nowhere stands secluded in the woods of a Cleveland suburb.

Ruins of a historic medical facility sits eerily by the water.

The NBA player's elaborate former home is now a ghost of its old glory.

An abandoned amusement park hints at the twisted history of the Newfoundland Railway.

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

This abandoned mine and power plant was built atop land once given to Revolutionary War soldiers.

A lost cemetery stands forgotten on a hilltop, known only to the older residents of Pomeroy.

This schoolhouse for Black American children is one of the oldest remaining in southeastern Ohio.

The headquarters of a pioneering cast iron and cast aluminum cookware company is in ruins, but still standing.

Canada's oldest railway tunnel is illuminated in a rainbow of color as it passes under the streets of this small city.

A 19th century hat factory still stands as a crumbling ruin in upstate New York.