If you had any doubt as to the reproductive power of Koi, this story should make you a believer...

Abandoned Bangkok shopping mall becomes incredible koi pond after years of neglect.  The unique aquarium formed after the roofless, four story structure puddled feet of water in the basement, creating a 1,600-square foot water body. Thai locals added Koi to the water to combat a growing mosquito infestation.

An abandoned shopping mall in Bangkok, Thailand has turned into a massive aquarium filled with thousands of fish. Incredible images of the water-filled New World mall show the bizarre contrast of a decrepit, unused escalator soaked with water, fish swimming by as natural light filters into the roofless, four-story structure.

The mall was first built in the 1980s as an 11-story building. But the top seven levels were not approved in the original construction permit, forcing it to shutter in 1997, according to the website Coconuts Bangkok.

One those floors were removed, the mall was left empty - and roofless - allowing rainwater to puddle and pool into several feet.

The “man-made” waterbody, measuring some 1,600-square feet, became a breeding ground for mosquitos, though, annoying vendors and residents near the mall.

Locals added Koi, a large species of colorful carp, and they quickly reproduced, creating the bizarre aquarium filled with fish.

Pictures of the aquarium have gone viral this week and the pond, normally visited by nearby locals who feed and watch the fish, has attracted tourists, the Bangkok Post reported.