Human: Make a concise location description of a foreboding scene inside a building tower with brass and copper ornamentation and a crusted brown stain. Assistant: 
Interleaved brass and copper ornamentation gleams from the edges of an arched niche along the western wall. Nearby, the smooth facade of pale sandstone is marred by a crusted brown stain, as if something has slid down the wall into a heap, but the source of the blotch is nowhere to be seen. A faint iron tang clings to the air.