I had a terrible time figuring out how to get the stonework the way I wanted it to look, until I finally gave up and drew the normal map in Photoshop by hand.
This picture has normals on the stone work:
There’s actually no light source inside the structure on the above picture. I think it’s all just lit with light bouncing off the normals.
The image below is from a couple days before (made before adding normals; it was so dim inside that I cheated and put a point lamp in the center tower):
