I saved them! :), Here are my first 9 thumbnails about my lair. I was thinking about a central tombstone that is huge in the center of the cave/tomb. The light coming from it I was thinking maybe a the sun light coming through the top of the cave, and maybe having some water in the cave to give it a sense of holiness. Also rivers start at the top of mountains so this could be the area where the river starts from, hence the water inside of the tomb.