Singapore - Botanic Gardens
The Garden covers an area of around 52 hectares. It is huge for the land-scarce island of Singapore. There are many attractions including 3 lakes, an orchidarium, a mini-rainforest, a ginger garden, etc.
If you don't have much time, head to the entrance at Holland Road. Take a quick walk around the Swan Lake, then head back to the Green Pavilion for a nice cold drink. It's a great way to spend a couple of hours and get some much needed exercise.
If you are into nature photography, the Garden provide great photo-opps.