​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.