Experts have warned people to stay away from the Icelandic volcano Hekla - dubbed the "Gateway to Hell" - as the volcano could blow "at any minute". Experts say pressure is building up within the volcano, and an explosion could occur anytime, without warning. Iceland is located on a divergent tectonic plate boundary on the mid-Atlantic Ridge. There are 30 active volcanic systems (out of 130) in the country. Hekla volcano is a stratovolcano located in South Iceland. It is 1,491 meters high and is also a popular tourist destination. The volcano has erupted regularly in the past - approximately once every 10 years between 1970 and 2000. Scientists believe Hekla have erupted about 20 times since 874 AD. During the Middle Ages, it was nicknamed "Gateway to Hell" by Europeans. However, the volcano has been quiet for the past 16 years, leading scientist to believe that it is building up for a major outburst. Hekla is a stratovolcano in the south of Iceland with a height of 1,491 meters (4,892 ft). "Hekla is a dangerous volcano," University of Iceland Geophysics Professor PÃ¡ll Einarsson told Icelandic news agency Visir. According to Professor Einarsson, who has studied the peak in much detail, "Hekla is ready at any moment." "We could be looking at a major disaster when the next eruption begins if we are not careful." Professor Einarsson says a powerful explosion in the volcano would put many lives at risk. There would be travel disruptions also because many planes fly directly over Hekla daily. A powerful eruption is also likely to impact flights to/from the UK. "There are also 20-30 planes full of passengers flying right over the top of Hekla every day," Professor Einarsson said. "This is a risky moment which we need to take seriously." Einarsson reveals that Hekla is showing pressure readings which are higher than they were during the eruptions in 1991 and 2000. In its last eruption, Hekla caused a pyroclastic flow, thereby producing a wall of gas and rock that reached 450 mph. Just 30 miles away from Hekla is located another active volcano - EyjafjallajÃ¶kull - which most recently erupted in 2010. The massive plume of volcanic ash produced after the blow went into the atmosphere, resulting in grounding of air traffic over Europe and a knock-on effect on international flights. The shut down of airspace from April 14 to 25 that year had left millions stranded around the world.