The Singapore Zoo, formerly known as the Singapore Zoological Gardens and commonly known locally as the Mandai Zoo. The zoo was built at a cost of $9 million granted by the government of Singapore.It is operated by Wildlife Reserves Singapore. Since 1973, Singapore Zoo has been known for having among the most beautiful wildlife park settings in the world, where animals roam freely in open and naturalistic habitats. There are about 315 species of animal in the zoo, of which some 16 percent are considered to be threatened species. The zoo attracts 1.7 million visitors each year.