You should probably go to Commonwealth Forest Park, Petaling Jaya. It is just like more nature, where there is a lot of trees, and we feel like we are in a forest.
There are so many things to do in the park such as Camping and Cooking Out, Jungle Trekking, Mountain Biking , Jungle & Waterfall Photography, Mountain Biking, Horse Riding and more. The park is divided into lower forest, river and waterfall (for camping) and upper jungle (for recreation amenities).
Hope this helps :)