Cod Rocks is named for the fish that were originally caught there, and the broken, uneven terrain that forms the local geography. A mess of cliffs and shallow channels and pools in the chilly northern Notal coast, with a few conveniently protruding formations that have over time been dotted with piers and fishing huts, and then half-protruding structures built into the water in the merfolk style.

Cod Rocks was not actually inhabited in the time of the Cataclysm, and has escaped most direct results of it. No large-scale destruction, and only ambient risk of horrible monsters. It's a quiet place in many respects. The merfolk rearranged the underwater stones and channels, created sheltered pools and caves and coves, dug out with sorcerous power and raw muscle, and the surfacers assisted in their own way, with the location long being one of the few reliable trading posts where mer of the far north could exchange meat and skins and treasures of the ocean floors for smelted metal, woodcrafts, and other such things.

The trade waxed and waned over thousands of years of history- Changing hands from one polity to another at times, being abandoned after a famine or destroyed in a monster attack at others. The grandiose stonework, however, that reshaped large parts of the area both above and below, mostly endures even if the cultures that built it have faded, including some mad genius's work in blasting and fracturing rock down to a region of volcanic activity, creating a semi-artificial hot spring in the hills and a number of elaborate worked and decorated channels spilling down.

In the modern day town, you can find a healthy if somewhat modest cottage industry working with seafloor resources. Fishing, working with coral, processing certain species into dyes or oils or textiles for trade. Further away, natural beauty blends with ancient shaping, with crumbling stairs and murals, a labyrinth of forgotten, collapsed, repaired, and sealed tunnels. The old caves and pools stretch surprisingly far, with many forgotten sights and occasional rumors of treasure, and of course, the hilltop hot spring temple that cascades warm water down to a series of pools and reservoirs even in winter is a must-see sight.

In one of these half-forgotten chambers, where water wells up in a series of circular pools only to cascade down again due to some mysterious natural or engineered force, magic that has built up and up and up reaches a critical point and undergoes a phase change, rippling out into a hole between worlds as latent energies discharge and balance out again.