Syasstroy (Russian: Сясьстро́й) is a town in Volkhovsky District of Leningrad Oblast, Russia, located near the mouth of the Syas River, at its confluence with the Valgonka, close to Lake Ladoga, 140 kilometers (87 mi) east of St. Petersburg.

[2] Within the framework of administrative divisions, it is, together with ten rural localities, incorporated within Volkhovsky District as Syasstroyskoye Settlement Municipal Formation.

[4] The economy of Syasstroy is dependent on just one enterprise, the paper mill, which makes it potentially very vulnerable to economic crises.

[11] The federal monument is the tomb of the author Sergey Semyonov, who died in 1942 in Syasstroy Military Hospital from pneumonia.

The local monuments are two tombs of soldiers fallen during World War II and a house where Sergey Kirov stayed when he visited the construction place of the paper mill.