<human>:  When did the first written law code appear?
<bot>: The first written law code was the Code of Hammurabi, which was written around the 17th century BC. The Code of Hammurabi is a set of laws that was written on a stele (a stone slab) and set up in a prominent place in Babylon. The Code of Hammurabi is considered the first law code, and it is the oldest written law code still in use today.