| Category | Rivers |
| Continent | Brucrumus |
| Region | Onvorn |
| Map | Igreshand |
The Black Spiral is an expansive Underdark river. Originating at Tara-Har, it flows into the Ebonmurk. The river's breadth varies considerably, ranging from several hundred feet to a full mile wide. The Black Spiral served as the central lava tube for the once-dominant volcano at Tara-Har.