Mazandaran is one of the richest provinces of Iran as regards natural resources. The Caspian Sea is the world’s largest lake on which five countries are situated: Russia, the Republics of Azerbaijan, Kazakhstan and Turkmenistan, and the Islamic Republic of Iran. The last has 992 km of coastline along this lake, most of it over the north of Mazandaran, More than 15 cities and towns of Mazandaran lie on the coast, the most important of which are Ramsar, Tonekabon, Chaloos, Noor and Babolsar. Indeed, this coast is one of the loveliest seaside resorts anywhere in the world. More than 350 rivers run from the Iranian territory towards and into the Caspian where over 100 species of marine creatures may be found, the most important being the sturgeon, salmon and kilka. The salt content of this vast lake is 12.7%. The temperature of the water of this lake is 24-26°C in summer and 10-12°C in winter which makes it an ideal coast for water sports especially in summer. So, every year hundreds of thousands of tourists visit this coast. Enormous amounts of crude oil and natural gas lie below the bed of the Caspian Sea which is being exploited through offshore drilling in places. Mazandaran has 15 lakes and swamps within it which favorably influence the province’s climate and are in themselves very attractive tourist resorts and natural features. Among these are: Valasht south of Chaloos, Khezr-e-Nabi close to Noshahr, Shurmast near Savadkooh. Sarandon near Saary and Palangan close to Neka, are the major swamps. Many a city in Mazandaran lies on the banks of a river. The rivers of this province provide water in abundance and also delightful scenery. The river of Haraz, 100 km long runs through Amol, Tajan (140 km), through Saary, and Chaloos (72 km), are among the major rivers of this province. The inactive volcano of Damavand makes the slopes at the foot of the Alborz range rich in mineral water springs which are used in curing arthritis, skin and digestive diseases. The most outstanding of these are: Kelardasht close to Chaloos, Esk and Larijan near Amol, and a number of springs close to Ramsar. Mazandaran also has many beautiful waterfalls which are also great sources of attraction for tourists, notably Harijan close to Chaloos, Timreh and Shahandasht near Amol, Darabkola close to Saary and Yakhi (Iced) not far from Peak Damavand which is therefore frozen throughout the year.