Human: Make a concise location description of a religious scene inside a tunnel tower with a mosaic. Assistant: 
Vast slabs of riverstone interlock with barely visible seams along the tunnel's walls. The stones' imposing size lends this passage a silent, brooding air, a sense of majesty requiring reverence. Some skilled craftsman has laid an intricate mosaic on the tunnel floor, though its image and the story it conveys are now obscured beneath a layer of dust and soot.