Sevastopol or traditionally Sebastopol is a city located in the southwestern region of the Crimean Peninsula on the Black Sea. As a result of the 2014 Russian annexation, the city is administered as a federal city of the Russian Federation, though Ukraine and most of the UN member countries continue to regard Sevastopol as a city with special status within Ukraine. Sevastopol has a population of concentrated mostly near the Bay of Sevastopol and surrounding areas. The location and navigability of the citys harbours have made Sevastopol a strategically important port and naval base throughout history. The city has been a home to the Russian Black Sea Fleet, which is why it was considered as a separate city in Crimea of significant military importance and was therefore once a closed city. Although relatively small at, Sevastopols unique naval and maritime features provide the basis for a robust economy. The city enjoys mild winters and moderate warm summers; characteristics that help make it a popular seaside resort and tourist destination, mainly for visitors from the former Soviet republics. The city is also an important centre for marine biology; in particular, dolphins have been studied and trained in the city since the end of World War II.