The River Trythos is a river in Andoras in The Wetlands. The longest individual river on Andoras, the Trythos is also unique for not reaching the sea; its source is Lake Litrum, in the lowlands of The Wetlands and near the Moonlyt Peaks. Instead of emptying into the ocean, the River Trythos ends in southern Gardoria, where it forms a small basin that is said to have been the birthplace of Gryge of Dermii -- however, the river's course would have almost certainly changed since his time, and this story is apocryphal at best.
The River Trythos has been a lifeline for those who live on its banks and in the range of its watershed, and almost all 47 Tribes of Gardoria were originally based alongside it. Traditionally, the entire river has been within the realm of Gardorian influence, but de jure territory has always dictated that the headwaters lied within the Wetlands.
The Confederation of the Trythos is also named for it, and the Gardorian region that it weaves through is rich agricultural farmland; an oddity in a paramouncy known for its thick, impenetrable forests. It shares a tributary that does reach the sea, known as the River Melthyos, but there is disagreement over whether the Melthyos is a tributary of the Trythos, or a separate river on its own due to its own historical importance.