The top sanctuary was the very first design.  It was far too fanciful and not nearly defensible enough.  I didn’t like any of the archway designs, wasn’t really sure why I hated it so much, and decided to let the “idea of sanctuary” marinate for a while longer before I tried again.  That led to the one that looked more like a castle, with the towers.  It was better, but still not what I wanted.  I eventually decided on a spherical design – though only the top half is visible, it is also spherical in shape underground.  The three little half spheres were my attempts to visualize that.  The larger webbed one to the right was a variation on the more final design – the most interesting thing about that one is that it has all my attempts at calculating how big this thing would actually be, and whether or not the courtyard would have enough space inside for the place to be self-supporting with regards to food (the answer was no).

This does not actually include the design I based the current sanctuary off of, because that one is covered in spoilers.  I’ll have to post that one some other time.