The concrete skeletons of an abandoned Swedish town hide among the trees.

An abandoned Jewish sanatorium is tucked within the woods of Poland.

This once sprawling resort now sits abandoned, filled with graffiti and vibrant colors from an era long passed.

Abandoned since 1998, this train station has become an oasis for urban explorers.

Tucked away in the forests of Indiana resides an abandoned waterslide that is now a popular graffiti haunt.

This now-defunct synthetic fuel plant was once a major cog in the Nazi war machine.

This old, abandoned hotel offers magnificent views.

Named after a bandit and the star of several Hollywood prehistoric landscapes, these sandstone formations are a historical part of the Los Angeles natural landscape.

Each year these high desert hills are absolutely covered with poppy flowers in a surreal show of nature.

A once grand hotel is being retaken by the wilderness it once capitalized on.

An eerie, derelict amusement park in Berlin.

A beautiful 19th-century mansion slowly crumbled and became a 'ghost house' after World War II.

The abandoned "Ghost Mansion" was left to decay in the mountains of Northern Italy.

This abandoned Victorian-style house was built in 1884.

Not far from a popular beach, an unfinished, abandoned mansion for Bulgaria's last communist dictator.

The sign at the garden gate reads: "These Plants Can Kill."

The internet as provided by a James Bond villain.

The now-abandoned Fascist summer colony served a dark purpose during World War II.

An abandoned 146-acre summer resort slowly being reclaimed by nature.

The remains of a 19th-century school and living quarters are perched atop a mountain surrounded by a thick tropical forest.

A 1,500-year-old, 3-story subterranean city where ancient Persians took refuge in times of war.

A subterranean relic of the Spanish Civil War hides below this picturesque park.

Fortifications built for a Soviet invasion that never came now sit abandoned in a losing battle against nature.

The abandoned remains of this once-thriving hotel looms over the city, awaiting an uncertain future.