 It's estimated that 300 of the planet's estimated 700 mud volcanoes sit in Gobustan, Azerbaijan and the Caspian Sea.Many geologists as well as locals and international mud tourists trek to such places as the Firuz Crater, Gobustan, Salyan and end up happily covered in mud which is thought to have medicinal qualities.The nature of Gobustan is much more suitable than other regions of Azerbaijan.