The Sungei Buloh Nature Park (1 Neo Tiew Crescent, +65 793 7377) is a great place for bird-watching, being a regional stopover for birds on their North-South migrations.
An 87-hectare wetland reserve, the park is a little less than an hour's ride by car from the centre of town. Admission is SG$ 1.00, and it opens from 07:30 -19:00 on weekdays and 07:00 19:00 on weekends and public holidays. The park gives you an idea of the mangrove swamps that once surrounded Singapore.
There's a visitor centre, boardwalks and bird-watching hides, from which you can spot night herons, or the white-breasted water hen. Also keep a lookout for various species of butterflies, mud-skippers and monitor lizards. If you're interested in aquaculture, prawn and fish farming is carried out in the park.