PEIPUS, or CHUDSKOYE OZERO  , a lake of north-west Russia, between the governments of St Petersburg, Pskov, Livonia and Esthonia . Including its southern extension, sometimes known as Lake Pskov, it has an area of 1356 sq. m . Its shores are flat and sandy, and in part wooded; its waters deep, and they afford valuable fishing . The lake is fed by the Velikaya, which enters it at its southern extremity, and by the Embach, which flows in half way up its western shore; it drains into the Gulf of Finland by the Narova, which issues at its north-east corner .