Human: Produce a detailed written description of a dreary scene inside of a medieval bank with a calendar, exchange rate board, and a wall. Assistant: 
A small square hole is cut into the stone wall, leaving just enough room to speak to the clerk behind it and to slide coins back and forth -- security is no joke at this bank. The only break in the monotony of the grey stone walls is a plain exchange rate board and a small calendar set into the wall.