Rising more than 10,000 feet from lush forest and fields in the center of Java in Indonesia, two perfectly shaped stratovolcanoes stand side by side. The summits of Sundoro and Sumbing are less than 10 miles apart, surrounded by countless small farms that grow rice, sugarcane, and other crops in the fertile volcanic soil. A narrow highway between the peaks is dotted with guesthouses, cafes, and outfitters: Each year, thousands of hikers pass through on their way to tackle the trails that lead up on either side. From the ground,…
