The City of Deepsand refers to the sovereign city-state of Deepsand, located at the bottom of the Sapphire Ocean north of the western continent and only bordering Ky'Pla maritimely. This indigenous community is made up entirely of Merfolk, a race of acquatic humanoids. Merfolk are fully sapient beings, and they live solely in the city of Deepsand, a sprawling, multi-layered city sitting on the ocean floor. Similarly to Irendall, they have a rudimentary, loose form of government and are mostly a tribal, hunter-scavenger society. Despite their older way of life, Deepsand ambassadors have interacted with other nations and have requested to be left undisturbed and for their slice of the ocean to be untouched, a request that has been so far honored.

Merfolk used to inhabit most of the Sapphire Ocean, and similarly to Thri-Kreen history and the Siwaken nation, they were mistakenly attacked under the assumption that they were sea monsters. They lived in nomadic clans who frequently battled for resources and survival, and were known among surface dwellers for their singing: while similar to whale song, merfolk song was melodic and sounded like a gentle humming. It is partly due to merfolk attacks on surface ships that sailors began to hunt them down and exterminate them. Reduced to low numbers, the remaining clans stopped their infighting and fled the equator area that was becoming more and more populated with sea traffic. Chased down by fauna, they eventually met up with another group and established a settlement. After time had passed, they cautiously got the attention of Ky'Pla, and were recognized by the world's nations.