The New World Mall in Thailand was originally planned to be an 11-story highlight of a Bangkok neighborhood, but the project was abandoned in 1997 after the structure was found to be in violation of the city's four-story limit on building heights. The top seven floors were demolished, and the remaining four floors were left to ruin. A fire in 1999 left the remaining structure without a roof, and the ghostly mall began to fill with rainwater.

The water-filled building eventually became a major health hazard as a breeding ground for mosquitoes, so an unknown local began stocking the flooded mall with fish, reports the travel blog A Taste of the Road. The fish thrived by consuming the mosquitoes and began to reproduce. Today the fish have virtually taken over the mall. The waters are thick with thousands of koi, catfish and (according to some reports) tilapia, which swim among the escalators in this unexpected urban aquarium. 

Shops around the mall sell fish food to tourists lucky enough to stumble upon this surreal abandoned wonder, but locals are protective of their fish, mostly choosing to keep the exact location of the mall a closely guarded secret. 

"It is quite bizarre — I was really surprised when I came across it. It is literally three blocks away from backpacker central, but nobody is even aware it is there," said Jesse Rockwell, a traveler and blogger who stumbled on the site. "It was very quiet in the mall, I could only hear the sound of splashing fish, even though it's close to a main road."

"A sign written in Thai outside says 'Do not throw anything into the water' — so people are trying to protect the fish," he added.

You can view some amazing pictures taken of the abandoned mall and its population of swarming fish at Imgur here

Unfortunately, with news of this urban aquarium going viral after the publication of these pictures, local Bangkok officials have closed the structure to the public. Inspectors are moving in, and if it is found to be unsafe, what remains of the building will be demolished. Should this happen, the fate of the thousands of fish that call the mall home would be up in the air. They would have to be removed, thus ending their reign in this eerie, post-apocalyptic-like structure. 

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Bryan Nelson ( @@brynelson ) writes about everything from environmental problems here on Earth to big questions in space.

Is flooded mall the world's largest urban aquarium?
Thousands of fish swim among the escalators in this surreal flooded mall in Thailand.