In this room again it is the fireplace which is of interest. It is in keeping with the style of the room with an oak surround to match the high status fixtures for the master of the house. The fireplace has man-made rocks i.e. bricks as the hearth. These are fire bricks and will have been baked in a kiln to a higher temperature (>1600 °C) than normal house bricks (900-1200 °C).
Exit the room and turn left into the corridor and then next left.