Home to the world's greatest concentration of mud volcanoes, the landscape around Baku might be described as messy, bubbling, and sometimes explosive. The country is thought to have nearly 400 mud volcanoes and while they never grow to the size of a normal volcano, topping out at around 10 kilometres in diameter and 700 meters in height (among the largest mud volcanoes in the world are Boyuk Kanizadag and Toraghai, both in Azerbaijan), they do occasionally get the chance to show off.
Mud volcanoes occur where tectonic movement allows subterranean gases to escape to the surface. A few of these gas leaks are constantly on fire, shooting small perpetual flames into the air, and some believe that these perpetual flames are strongly connected to the appearance of Zoroastrianism in Azerbaijan about 2,000 years ago. Located a 1.5-hour drive from Baku, the mud volcanoes at Dashgil near the Gobustan Reserve are the most popular to visit.