The Trešnjevik smail river springs at the foot of the Trešnjevik pass (1573 m above sea level), formed by "Water Source" and "Smaller Watercourse". In the upper course, on the left side, it receives small streams from the localities of Garevina and Osoja, while in the middle course, it receives streams Lomovi 1 and Lomovi 2. It flows into Rajova (Rajović) Rijeka near alluvial plains Milićević and alluvial plains Rajović. In the middle course, the Trešnjevička River on the left side formed the alluvial plain of Novović, at the foot of Lomovi a small alluvial plain on the right and left side and the most widespread in the basin of Rajova (Rajovića) River -alluvial plains Milićević. In Trešnjevičkoj smail river their habitat in the river and found the brown trout, which at the present time there are less and less. There are many reasons for the poor state of the brown trout. The two most destructive techniques are dynamite hunting, followed by net hunting. On Trešnjevik environment and you can spend a great time -skiing, walking, doing sports or hunting and fishing, and the environment itself is a great choice for all kinds of recreation in nature, as well as for all lovers and admirers of almost untouched nature.