The Mount Irasu is the world's famous active volcano, located in Cartagena, Costa Rica, and has erupted twice in the past 100 years. Now it is a nature reserve, and the crater on the mountain has formed two crater lakes, which are very beautiful. But here, absolutely, is a wonderland on one side and hell on the other, because there is no plant in some parts, and the hillside on the other side, dense forest, is a stark contrast.