The massive chain of mountains running along the northern part of Weltluna is known as the Backbone of the Great Serpent (大蛇の背骨 Daichi no Sebone?) due to its shape. This expansive yet natural wall prevents anybody trying to escape to the north. While many adventurers have tried to climb these mountains, not one of them has yet to reach the top. What has long been known as "The End of the World" from ancient times, this mountain range separates charted territory from the lands to the north.