Mud volcanoes. They lie about 10 km south of Gobustan. These volcanoes are quite unique as they are not as high as usual volcanoes, with height getting maximum 2 meters. Still, nearly half of the mud volcanoes in the world are located in Azerbaijan (more than 350 out of 800 in the world) and the greatest mud volcano in the world is also in Azerbaijan (1000 meters high). The mud bubbles right from the inside of the volcano and it is usually cold, rather than hot as you might think. Also, the mud is said to be good for face and is commonly used for medical reasons.