istiqlal mosque is located on former wilhelmina park, thus prior of mosque construction, there are numbers of decorative plants and trees planted in the garden. some of garden's old large trees might be hundred years old. the park is also the location of a river branch, the distributary of ciliwung river, completed with floodgates. the original river branch went westward to molenvliet and turned northward along canal towards its estuarine in old batavia. the other branch turned northward to a floodgate which drain eastward along a canal in front of pasar baru, the canal turned north along jalan gunung sahari, all the way to ancol in the north.