Dubrovnik, a town, port and tourist centre of the southern Croatian coast. It lies at the foot of the limestone Srd Mount (412 m), in a valley enclosed to the south-west by the Lapad plateau and a smaller reef with the oldest part of Dubrovnik. The ancient town core was connected with the suburban zone on the other side of the valley by levelling and filling up of a marshy valley between the Gruz Bay in the north and Stari Porto (Old Port) in the south, as well as by the construction of the Placa (Stradun). Stradun thus became the centre of the town and its main street, connecting two opposite town gates: the Ploce Gate in the east and the Pile Gate in the west. Upon the construction of the port in the Gruz Bay, Gruz was gradually annexed to Dubrovnik and became an integral part of the town. Later on, Dubrovnik extended also to the Lapad peninsula, to lower parts of the Srd slopes and outside the town ramparts toward Zupa.