Cities are havens for weirdness. From communities built around garbage to dogs that ride the subway, urban environments have fostered all manner of weird patterns. Here are the 10 freakiest urban ecosystems on the planet.

As you may have noticed, we're obsessed with the Kowloon Walled City. Prior to the labyrinthine city's demolition, a Japanese research team drew up this huge cross-section map. It's in Japanese, but it's nonetheless astounding. [Deconcrete via William Gibson]

The fortress-like Kowloon Walled City of Hong Kong was demolished in the early 1990s, but a German documentary crew braved the sprawl in 1989 and captured amazing footage from inside this sunlight-less patchwork metropolis.

Cities are havens for weirdness. From communities built around garbage to dogs that ride the subway, urban environments have fostered all manner of weird patterns. Here are the 10 freakiest urban ecosystems on the planet.

A dystopian megacity, in which buildings merge together to become a single solid block, is the stuff of science fiction — but it already happened, in Hong Kong. The Kowloon Walled City was packed so tightly, it became an arcology.

In the near future, we'll all live in tightly packed arcologies, including ocean cities — where we'll shoot at each other and fire rocket launchers in the air. This gorgeous "seagoing eco-city" comes from the first-person shooter Brink.

The idea of an arcology, a single hyper-structure that houses an entire town or city, has haunted science-fiction stories like H.G. Wells' The Sleeper Awakes, Judge Dredd comics and Larry Niven novels. But now they're building one in the desert.