"Sea fortress" - Reconsidering what is useful to do

I've been making maps and blueprints of the environment, but just realized that Concepts will not make any sense after, so I kind of finished off the first sketch that I had. I really wanted to make it much more detailed and maybe just leave in the line-art state, but the final thing was a bit disappointing, so I've done everything in the same way as I always do what was not that interesting too. It gives maybe too much of ambiance for the soundtrack. Anyway, after this I'm going forward to architectural blueprints. After that I might reconsider creating clear map of area. I might also need more concepts from other angles and from the inside too.