The word fjord is a landform which in international technical language within geology / geography is explained as a deep, narrow and elongated sea or lake channel. The opening towards the sea is called the mouth of the fjord and is often shallow. The innermost part of the fjord is called the fjord bottom. If the sea channel is wider than it is long, it is a bay or a cove. In common, popular language, any long narrow bay is often called a fjord in Norway. Byfjorden in Stavanger is approximately 10.5 km long. Several bays and coves are located along the west side of the fjord. Tungvika is just south of Tungeneset, Randabergbukta is close to Randaberg, Ladbergvika is another bay in Randaberg, Harastadvika is further south. Dusavika is an industrial and base area for the petroleum business in Stavanger. South of Dusavika is Tasta, a district in Stavanger. At Buøy, a peninsula at Hundvåg, is Rosenberg Verft. Drive "under" the fjord From Randaberg to Sokn, the almost 6-kilometre-long underwater Byfjord tunnel goes under the Byfjord to Rennesøy. The tunnel is part of the Rennfastsambandet (Rennfast road connection) along the E39.