| Category | Depressions |
| Continent | Brucrumus |
| Region | Grashakh |
| Created | 21 Temporal 1020 |
| Map | Thingrorn |
Named after the emerald-hued dragon Mathongrarg, this vast cavity was formed when the Ink Sphere touched down here in 1020. Over the ensuing days, the colossal object gradually descended, eroding the bedrock with its movement. In its aftermath, it left behind a shaft measuring 1,100 feet in diameter.