I've been inside and to the top of the lighthouse. Unfortunately, there's nothing too exciting inside the structure. There are some stairs, and then a very tiny elevator (it can hold only one or two people) that brings you to the top. The inside of the structure is just scaffolding -- it's not decorated or furnished.
At the top, by the actual light and mirror, there's a small control panel that controls the speed of rotation of the light. There's a beautiful tile design on the ceiling above the mirror that you can't fully appreciate from the ground. Someone put a lot of time and effort into it.
The view is incredible!