Just because the land and sky were the most densely populated areas within Tehom, did not mean that they were the only ones.
The sea, while not as populated as the other two domains, is still every bit as beautiful.
And since the multiple oceans across Tehom are separate, finite spaces, their communities are that much closer as a result.
Diving into these crystal blue waters, one will witness a never-ending variety of sea life.
Everything from the average household goldfish, to the slightly-above average kraken, who just so happens to be a highly respectable bartender.
The infrastructure is designed to be open, breathable, and glass-like with very little wood or metal involved in it's construction.
Magic was spelled along the open doors for privacy and to obscure the vision of others who might be eager to peep.
The grandest of all underwater structures was a castle that looked like it was chiseled from diamonds (It was. Partially.)