In addition to the winding road Knjazevac - Pirot, there is a favorite view of the passengers - Bigen waterfall on the Stanjinska River.
On the site there is a marked walking and cycling trail of 3 km long, which leads along the Bigreno stream and the Monastery of St. Onfurius. However, many from this resort leave without seeing the cascading limestone lakes on the river above a large waterfall.
The unusual blue-green lakes are hidden in a dense plant a few hundred meters above the waterfall. Their natural beauties are known, mostly, only to the local population.
The source of the Bigen Creek is about three hundred meters upstream of the limestone basins and is known to the people as "crazy spring".
From its cold and minerals of saturated water, through limestone branches, trees and leaves, the limestone creates a dam. Bigar catches on the mass of wood in the water and creates an impenetrable dam above which the lake forms. From it water expands and through the next obstacle in the riverbed, the bigar again creates a new dam and a new lake.
On the move above and below the lake, the wheat was once milled by twelve watermills. Watery stones have not turned around for a long time, and the rest of the building has grown green.