In the past couple of years a new visitor attraction has been built in Singapore, near the Marina Sands Bay Hotel.  Gardens by the Bay have two Eden Project style glazed domes and then an open garden which has some “living tree” structures which must be 50m tall with foliage grow up them and from which you can walk along a raised walkway.  The Cloud Dome is cool (probably around 17 degrees) and there is a waterfall and some raised walkways, like in this picture.  I would certainly recommend a visit for a few hours.  I went in the early evening and watched a light show at 19.45.  The Domes cost around $30 to visit.