Orechovets is an island with the fortress Oreshek (Nöteborg in Swedish, given the name Schlisselburg/Schlüsselburg after its re-conquest by Peter the Great in 1702). The island is situated in Lake Ladoga at the inlet of River Neva. The fortress was erected sometime in late 13th century or in beginning of 14th century.

The name of the island refers to Nuts in both Swedish, Finnish (Pähkinäsaari/Pähkinälinna) and Russian. The German name Schlüsselburg refers to Peter's perception of the fortress as the "Key to Finland".

In 1323, a peace treaty was made in Orechovets between Sweden and Novgorod (in English works mostly mentioned by its Swedish name as the Treaty of Nöteborg), with the first agreed border between Eastern and Western Christianity, running through present-day Finland.