The shallow-water Sea of Azov is a unique water area. Scientists believe it could be the rest of the ancient Tethys Ocean. That is the reason why a lot of forms of ancient flora and fauna can be found there. More than 400 life forms live in the Sea of Azov. Surface area of the sea is about 39 000 km², the maximal depth is 15 m and the average depth is only 7.4 m. That is why it is called the shallowest sea on our planet. Researches had been carried out and now the scientists know that the average age of the sea is between 23- and 460 mln. years. But the sea was not always the same. Long time ago it turned to the lake system. About 2-3 mln. years ago the water in it was fresh. In that period the sea level changed a lot so that influenced the seaside landscape a lot. So nowadays the seaside consists of a great number of different bays and spits what makes Azov maritime regions attractive for resorts and recreation zones. Also many of them considered National Natural Reserves.Seawater itself is an important curative factor as it has a positive influence on cardiovascular, nervous and digestive systems. These effect is due to the biogeochemistry of waters of the Sea of Azov. The average temperature of the water is about +18º C during 4 months a year which makes resort season in our city quite long. Annual marine evaporation is more than 920 mm, so the air is rich in iodine, bromine and other solts and micro-elements. Breeze aircirculation also plays an important role, it calms the heat and fills the air with salts and phytocides. The temperature of water in the Sea of Azov is 6-7º C higher than in the Black Sea: already in May it can make 26º C.