Graffiti has been found in very old cities. For example, in the Roman Empire, people wrote messages and drew caricatures on walls. Graffiti is also found in many places. Some people do murals of graffiti rather than just writing one mark in a location. It was used for good instead of vandalism. Probably the simplest graffiti is when a person cuts (or carves) the name of a lover on a tree with a knife.