Singapore has a few places where one can breathe surrounded by nature (yet still hearing the city noise). One of such places would be the area around MacRitchie Reservoir.
It's located in the central part of the island and the area around the reservoir is mostly covered by tropical forest with many trails - attended very often by people practicing long runs.
We took a long walk starting from the MacRitchie park, going towards the golf fields and observation tower.