For a steampunk look use several Redstone switches throughout the build, give it a dingier look, and fill it with bookshelves. For more of a fantasy, look use stained glass windows, torches, and more mythical-looking items to decorate.
However, once within the ground, this build could be any shape or size with more portholes looking out into the ocean.Players could make this more of a modern to science fiction builds to a steampunk or even fantasy build. This can be a bit more of an advanced build as players will need to be very precise when digging down into the rock and soil. One of the newer and more modern ideas is to build either an underground or mountainside underwater hideout that looks out into a body of water.
