The New World Shopping Mall was once a thriving 11-story mall but due to building regulations many of its floors had to be demolished. To make things worse, the mall suffered an arson attack which destroyed the structure’s roof and few years later the mall has being abandoned in 1999.. Not long after that monsoon rains flooded the lower floors. As a way to combat the spread of mosquitos and other insects breeding in the stagnant water, locals introduced koi and catfish to the former mall. Not only did the fish take care of the pest problem, they’ve thrived. It is now one of the world’s largest urban ponds.