Grand Triskele Lake

As the name implies, the Grand Triskele is broadly shaped like a trefoil, with three major limbs wending away from the central body along crooked paths that narrow as they approach the highlands just before the fimbulmist. The three limbs are known as the Southern Spur, Northwestern Spur and Northeastern Spur, respectively, and separate the variegated landforms between into the Northern Plate, Southeastern Plate, and Southwestern Plate respectively. The crookedness of these limbs make ascertaining the true boundaries of these plates difficult to ascertain, and many of the tributaries coming down from the highlands have never been accounted for, let alone traced back to their sources.   The Grand Triskele Lake is actually more of an inland sea than a lake proper, its world-spanning volume obfuscated in part by the narrows at its limbs and the numerous small islands spread across it. Early explorers from the Kingdom of Rosethorne thought they had found the edges, but, after the name was coined, exits from Rosethorne territory into the broader lake were discovered that put the lie to the notion that the Grand Triskele was merely a lake. Each of the three major 'continents' is surrounded by numerous smaller islands, as though parts of rock beneath were sheared off by glaciation in ancient times.   Though the surface geography of the Grand Triskele is relatively stable save for the presence of some volcanic islands, the subsurface charts have to be updated constantly to ensure safe navigation for seagoing vessels. The growth of massive underwater plant and coral structures, the activities of creatures like langostinites, and active geothermal activity change the structure of the seabed over time, occasionally giving rise to new bars and even islands where there were none before.

The Grand Triskele Lake is large enough that different extents of the sea can have wildly different environments and ecosystems. The Grand Triskele is mostly freshwater, though there are briny pockets in deep wells and underwater caverns where circulation is poor.