The old Mediterranean port of Kotor is surrounded by an impressive city wall built by the Republic of Venice and Venetian influence remains predominant in the city's architecture. The Bay of Kotor (Boka Kotorska; Bocche di Cattaro), one of the most indented parts of the Adriatic Sea, is sometimes called the southern-most fjord in Europe (though it is actually a submerged river canyon). Together with the nearly overhanging limestone cliffs of Orjen and Lovćen, Kotor and its surrounding area form an impressive and picturesque Mediterranean landscape. In recent years, Kotor has seen a steady increase in tourists, attracted by both the natural beauty of the Gulf of Kotor and the old town of Kotor itself. Kotor is part of the World Heritage Site dubbed the Natural and Culturo-Historical Region of Kotor.