Introduction to Su Sanjing: The small well in the center of the hospital is called "Su San Well". Su San fetched water here and washed clothes in the stone trough made of yellow sandstone next to it. This well is about two meters deep. The wellhead is very special. It only has a bowl-sized hole drilled in the middle of a large bluestone about 30 to 40 centimeters thick. The diameter is about 23 centimeters. People cannot put their heads into the hole. It is specially designed to prevent prisoners from throwing themselves into the hole. Well designed to commit suicide. Around the wellhead, there are deep marks left by the well ropes, which illustrates the age of this death row prison.