Sevastopol (English pronunciation, IPA: /ˌsɛvəˈstoʊpəl/ or /səˈvæstəpoʊl/) (Ukrainian and Russian: Севастополь; Crimean Tatar: Aqyar), formerly known as Sebastopol, is a port city in Ukraine, located on the Black Sea coast of the Crimean peninsula. The city, formerly the home of the Soviet Black Sea Fleet, is now a Ukrainian naval base mutually used by the Ukrainian Navy and Russian Navy. The unique geographic location and navigation conditions of the city's harbours make Sevastopol a strategic important naval point. It is also a popular seaside resort and tourist destination, mainly for visitors from the CIS countries. The trade and shipbuilding importance of Sevastopol's Port has been growing since the fall of the Soviet Union despite the difficulties that arise from the joint military control over its harbours and piers. Sevastopol is also an important centre of marine biology research. In particular, studying and training of dolphins has been conducted in the city since the end of World War II, initially as a secret naval program to use these animals for special undersea operations.