Тосненский район
The source is in swamps south of the settlement of Radofinnikovo. The river flows north, enters Tosnensky District, passes the town of Tosno, and essentially enters the suburbs of Saint Petersburg. There, it flows through Ulyanovka and Nikolskoye. In this area, limestone rocks occasionally form the banks. In particular, Sablinskiye Caves, disused quarries, are by the river. A stretch of Tosna between Nikolskoye and Otradnoye serves as a border between the city of Saint Petersburg (west) and Leningrad Oblast (east). The mouth/confluence abuts the west of Otradnoye, a town.