Poronaysky Nature Reserve (Russian: Поронайский заповедник) (also Poronaisky) is a Russian 'zapovednik' (strict nature reserve) covering Cape Patience, on the eastern side of Sakhalin Island in the Russian Far East. A specific purpose of the reserve is to protect rookeries for arctic birds on Cape Patience, which is a 65 km peninsula extending into the Okhotsk Sea. The reserve includes the southern part of the East Sakhalin Mountains, and the widest part of the Tym-Poronaisk dale. The reserve is situated in the Poronaysky District of Sakhalin Oblast, 50 km east of the regional city of Poronaysk. It was formally established in 1988, and covers 56,695 ha (218.90 sq mi).