Sungei Buloh Nature Park in the wetlands just south of Buloh Island in Singapore is a great place for bird-watching, being a regional layover 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 center of town.
Sungei Buloh Nature Park - one of the highlights of Eco-Tourism and Nature Reserves in Singapore and 18 Best Singapore Parks and Natural Spaces (Read all about Singapore here)
photo by Qingwu Zhou (CC BY-SA 3.0) modified
A visit to Sungei Buloh Nature Park gives you an idea of the mangrove swamps that once surrounded Singapore. There's a visitor center, boardwalks, and bird-watching hides, from which you can spot night herons, or the white-breasted water hen.
Besides birds, keep a lookout for various species of butterflies, mud-skippers and monitor lizards, as well. If you're interested in aquaculture, you can also find prawn and fish farming carried out in the park. Admission to Sungei Buloh Nature Park is S$1.
photo by Qingwu Zhou (CC BY-SA 3.0) modified