Oh, this is rather impressive. Behold Ruin, a cryptic 8.5-minute short film by the folks at Oddball Animation. In the post-apocalypse of Ruin, nature has reclaimed entire cities. Humans are still around, but verdant metropolises aren't as empty as they seem. Seriously, you'll want to give this animated short a whirl —…

If you ever find yourself 60 miles north of Vladivostok in the city of Ussuriysk, you can visit the crumbling Vozdvizhenka Air Base, where gutted planes sit in the open for trespassers to explore. Crazily enough, security's nonexistent here.

The Japanese theme park Gulliver's Kingdom was only open from 1997-2001 before a lack of visitors shuttered it. Until its decaying remains were demolished in 2007, the park and its 147-foot-long Lemuel Gulliver statue were prime destinations for urban explorers.

Now that J.J. Abrams' time-traveling prisoner series Alcatraz is locked in for Fridays next fall, let's take a look at the show's abandoned penitentiary setting, which has since been turned into a tourist attraction after closing in 1963.

Mike Petty took these shots at Wichita's Joyland Amusement park, which has struggled with bankruptcy and vandalism for the better part of the last decade. Joyland's name has taken on a greater irony, as it's become a dilapidated, depressing place.

70 or so feet underneath London's streets lies the unused mail rail system, a hard to reach subterranean system of postal tracks, cloistered away from human eyes. That is, until a gang of intrepid urban explorers cracked a secret entrance.

In China, the development of residential and retail property in certain regions outstrips the government's ability to keep these buildings occupied. An Australian film crew recently visited China's vacant real estate and saw these strangely silent cities firsthand.

In Inner Mongolia lies the mostly empty planned city of Ordos. The area was built for 1 million residents, but thanks to Ordos' cost of living, almost nobody lives there. Check out sparse photographs of this empty city.

In 1958, the United States tested the 18-kiloton "Cactus" nuclear device on Runit Island in the Pacific. 20 years later, Cactus' 350-foot-wide crater was filled with radioactive soil and covered with a 100,000-square-foot concrete dome. Worst vacation ever?

In northeastern Ohio, there's a bucolic airplane graveyard filled with the decaying remains of old jets, like this Vought F7U Cutlass. Here's an eerie video of these rotting old birds.