Singapore Zoo, Singapore
Take the MRT to Boon Lay, then get a bus from there. As zoos go, this is a pretty good zoo, particularly for the monkeys, which have a huge space to roam, and are free to swings through trees. What I don't like about this zoo, is the animals in cages, particularly the big species (lions, tigers, polar bears, rhinos), I found the polar bears upsetting, because he just lay there in 30+ heat, with only huge fans to cool him down, the enclosures weren't a good enough...