The abandoned grounds and derelict greenhouses of this once-magnificent Edwardian estate are now a nature preserve open for exploration.

An abandoned 19th century quarry in the middle of the woods, remade by unnamed wanderers into a massive series of rock thrones.

This abandoned ironworks was once the most important military supplier in America.

These World War I shooting range tunnels are now haunted halls of underground graffiti accessed through the roots of a tree.

This abandoned factory on the Hudson River once churned out a million bricks a week.

An abandoned asylum where patients have been forgotten but their possessions remain.