Nix

The original subterranean construction would've been extremely easily defensible. For that reason, any force that ruined it must have been formidable indeed.   As a ruin, Nix was plagued by undead of multiple varieties. Also inhabiting the area were twin hydroloths. These fiends were most likely bound to protect the tower, and the Heart of Theane within.   When the ruin was taken over by the sahuagin, the defensibility of the crack proved a tremendous challenge for the invading forces. It was only their overwhelming numbers and the Cake Squad leading the charge that allowed the sahuagin to be driven off.   Currently, forces from Calamand and Mir'assen are stationed there to prevent the sahuagin from returning.

According to histories mostly lost to time, the kuo-toa once created a vast and prosperous empire buried beneath the seafloor. Based on the stories told by today's kuo-toa, their kingdom was destroyed by demons known only as "Thought Eaters", leaving their wealth to lie forgotten.   For as long as civilization has existed in the Dawn Sea, treasure hunters have searched for the lost capital of the kuo-toa. Legends whisper of vaults full of gold, and magical treasures the likes of which the world has never seen.   It remained lost until a mysterious crack opened in the ocean floor. It was first discovered by a scouting party from Mir'assen, and first explored by a company of adventurers that would become known as the Cake Squad. The adventurers were driven off by the denizens of the ruin, but not hearing the distinctive music of the Hearts of the Sea.   After the adventurers fled, the sahuagin moved in. Their king, Icktrik, forced his way into the tower in the deepest part if the ruins, and claimed the Heart of Theane. From there, he launched a campaign to destabilize Calamand and Mir'assen in an attempt to conquer them.   Due to the efforts of the Cake Squad, the sahuagin were driven off and Icktrik killed. Both Calamand and Mir'assen have garrisoned troops there to protect the area from the shark-folk. Proposals to rebuild the city have stalled due to territorial disputes between the two occupying forces.

The city of Nix was built entirely into the seafloor, and the builders clearly built it downward as it developed. The mysterious crack has seen the entire ruin exposed to open water in a manner that seems almost deliberate.   Despite recent reports to the contrary, the city's buildings are made of a sturdy stone. Despite this hardy construction, most of the city is thoroughly ruined. Strangely, the buildings deeper in the crack are in better shape. The tower at the bottom seems almost completely untouched by time.