From there, the river flows generally into the north-west direction, along the Šumadija's geological bar into which the river carved its epigenetic valley and formed a watershed. The valley of Topčiderka is a natural route for the Belgrade-Niš railway.
From there, the river flows generally north-west, along the Šumadija's geological ridge, which the river has eroded to form its epigenetic valley and create a watershed. The Topčiderka valley serves as a natural route for the Belgrade-Niš railway.