Izhora
The Izhora (, ), also known as the Inger, is a left tributary of the Neva on its run through Ingria in northwestern Russia from Lake Ladoga to Gulf of Finland. The Izhora flows through Gatchinsky and Tosnensky Districts of Leningrad Oblast as well as through Pushkinsky and Kolpinsky Districts of the federal city of Saint Petersburg. The settlement of Ust-Izhora (lit. "mouth of Izhora") is situated at the confluence of Izhora and Neva, halfway between Saint Petersburg and Shlisselburg. The towns of Kommunar and Kolpino are located on the Izhora as well. The river is noted as the farthest  Swedish forces ever reached between the Viking Age and the Time of Troubles. The calculated length of the Izhora is , and the area of its drainage basin is . The river draws its water mainly from natural groundwater springs, snow melt, and rain water. The river has a sustainable underground water supply in both summer and winter, never drying up or freezing through. The source of the Izhora is located at the village of Skvoritsy, northwest of the town of Gatchina. The Izhora flows to the east, passes at the northern outskirts of Gatchina, and east of Kommunar enters Tosnensky District . There, for a short stretch it makes the border between Saint Petersburg (north) and Leningrad Oblast (south), returns to the oblast and gradually turns north. In Kolpino, the Izhora enters the federal city of Saint Petersburg. There, it flow north and joins the Neva in the settlement of Ust-Izhora. The drainage basin of the Izhora includes the northern parts of Gatchinsky and Tosnensky Districts, as well as some areas within Saint Petersburg.