Fabulous, not traditional and so not like anything I have seen which is just what you want from a fantasy fortress. I would leave the over-wide tops of those towers as they are, or at least don't narrow them down too much or they will lose their unique character. I would though, have only one entrance or at most two, a fortress should be credible and unless it's a whole fortified city it would be very unlikely to have more than one gate. Look forward to the finished item.