Grzegorz Gawlik on different continents and in different climates. Among other things, he discovered the highest lakes in the world on the Ojos del Salado volcano and found that the highest active volcano in the world is Llullaillaco. In addition, he explored more than 100 other volcanic sites such as geyser fields, geothermal fields, volcanic caves, volcanic deserts, volcanic plateaus, volcanic craters and cones, volcanic rock formations, lava fields. He climbed to about 100 peaks 4-, 5-, 6- and 7-thousand meters in the Himalayas, Andes, Pamir, Caucasus, Cordillera, High Atlas, Tanzania, Borneo and hundreds of lower peaks. During the expeditions, Gawlik explored
Hamgyong Mountains mountains on the peninsula. The tallest mountain in the range is Kwanmo Peak (2,540 m), the second-highest after Paektu (China's "Changbai"). Other notable peaks include Du Peak (2,396 m), Gwesang Peak (2,333 m) and Mount Dury (2,303 m). In total, ten major peaks and 62 subsidiary peaks of the mountains in this range are 2,000 m or higher. Hamgyong Mountains The Hamgyong Mountains (, , "Hamgyeong Sanmaek"), officially known as the Gangbaekjeonggan and formerly known as the or , is a North Korean mountain range. It lies in the northeast quarter of the country, extending for about southwest and northeast