Sea of Souls
At first glance, you behold the sea, you think. You stare out onto those sparkling waters and lose yourself in the motes of mesmerising blue. It isn't until much later, when the sun has set and the stars gleam in the endless mirror before you, that you realise this is no true sea... but the mistake is quickly forgotten, as another nebula catches your eye.The Sea of Souls lies at the centre of Takawaoku, serving as both the figurative and literal heart to the southern continent. It provides trade routes for the nations bordering it and those further beyond, and is fed by rivers trailing down from the mountains to both its north and south, as well as smaller rivers leading in from the forests to its east and west. No country contests a singular claim of the Sea of Souls; those who have tried in times past have inevitably had to defend against every other nation on the continent, and some further afield besides. Shiar has made the most significant change to the Sea in centuries, however, with the excavation of an artificial river to connect the "inner sea of Paiyu'um" (as they call it) to the outer seas, enabling greater trade. Rhaead once had a similar connection to the Manawa River, but changing tides and repeated flooding forced that shipping lane to be closed off. The inner sea has an immensely varied ecosystem, owing to the sheer amount of magic it has collected over the years and the variety of ways marine life can survive here. The 'mascot' of the inner sea is the Paiyu'um Sea Turtle, a small species of turtle characterised by its bizarre habit of attacking any boat in sight and strange socialisation patterns with other marine life.
A common sight where the lake meets the shores is the brilliant multi-hued shades of all the different corals growing in stunning reefs, small fish darting around them. Around the sea's southern edge, where it meets Osori, the signs of the Starsear's distant presence are distinct in the corals; they are dyed a blood-red, and even bleed despite the distance from the Starsear itself and the absence of any nearby Incarnadine.
Beneath the surface, things change. The Sea of Souls is one of the deepest lakes in the world, with measured depths sinking well beneath 5000 ft. In those depths lie hidden civilisations and years of history - and perhaps the root cause of the inner sea's usual name. At the furthest depths, the line between magic and world begins to blur; it isn't uncommon for divers at these depths to begin to see spirits of the Ethereal Plane overlapping them in that haunting mirror realm. This is the only place where leyfish have been located, pointing to the sea potentially being a leyline nexus or something close to it. It is said that one of the hidden civilisations beneath the waters sprung from the wreckage of Terra Arcana's fall, populated by some of the last remnants of those who refused to leave. If true, then in the intervening years, they will have adapted to the deep waters - their very bodies changed by the intense magics and pressure of the deepest depths.
With the advent of Gaia's Lament, we can't afford to travel so much... I worry for all the islanders on the Sea of Souls.