Into Iceland's Volcano

In spring 2010, the nearly unpronounceable volcano Eyjafjallajkull spewed ash clouds across Europe, bringing international air traffic to a standstill. Now, for the first time ever, a team of explorers descend into the nearby Thrinukagigur volcano crater - the only place on earth where it is possible to enter an old magma chamber. Inside the crater, the team finds crucial evidence revealing the inner workings of Icelandic volcanoes. (National Geographic)