Domchoong created an amazing aerial look at two of Indonesia's greatest geological marvels. Mt. Bromo is the highest volcano in a group of mountains known as the Tengger range of East Java. It's a very active mountain, and warnings are periodically issued during times of high eruption risk. Ijen is a well known crater, located to the east of Bromo near the very eastern end of Indonesia's most populous island. For reasons which will be clear once you see the video, it's known as the Blue Fire Crater.