The Frásnúr River is a major river that flows through Hjertlande in the Kingdom of Kalvete. Its headwaters begin in the Spine of the North before flowing and collecting into Lake Headwater in the Highlands. The river then continues to flow westward, eventually ending its journey in Flóanótt Bay.
The Frásnúr has been crucial to the development of Kalvete and its largest cities, including the nation's capital of Iskholde. Its waters are navigable from Flóanótt Bay to the edge of the Highlands, which has benefitted the nation's trade routes.