Ключевые слова: acid, action, asean, asia, backpack, blue, cloud, crater, crater lake, danger, dangerous, east, erupting, exploration, fog, gas, heat, hike, ijen, indonesia, island, java, java indonesia, ka wah ijen, kawah, kawah ijen, lake, lake of sulfuric acid, landscape, lava, mineral, mist, mountain, nature, rock, scenic, sky, smoke, steam, sulfur, sulfuric, sulphur, tourism, travel, trek, trekking, volcanic, volcano,