Odessa or Odesa is the fourth largest city in Ukraine with a population of 1,003,705. The city is a major seaport and transportation hub located on the north-western shore of the Black Sea. The predecessor of Odessa, a small Tatar settlement, was founded by Hacı I Giray, the Khan of Crimea, in 1440 and originally named after him as "Hacıbey" Odessa has a warm temperate climate. During the tsarist era many wealthy but sickly persons were sent to the city in order to relax and recuperate. This resulted in the development of a spa culture and the establishment of a number of high-end hotels in the city. Flora is of the deciduous variety and Odessa is famous for its beautiful tree-lined avenues which, in the late 19th and early 10th centuries, made the city a favourite year-round retreat for the Russian aristocracy. The city's famous Arkadia beach has long been a favourite place for relaxation, both for the city's inhabitants and its many visitors. This is a large sandy beach which is located to the south of the city centre.