In surface survey, the team walk over the study areas systematically, looking for pottery, tiles and (if they are lucky) a coin on the ground.
In the Platani valley, the sites - Roman to Medieval - were hidden under grain fields or olive groves. However, the soil had been turned over for cultivation bringing the artefacts to the surface. Madeleine Hummler organised the surface survey teams, ensuring that every sherd of pottery and tile was counted and the numbers mapped by metre square.
The places with the most tiles likely showed where a house or dwelling had been, while places with lots of pottery showed where people had been cooking and eating. And there was slag - a waste byproduct of metal processing - where people had been smelting or forging iron. The pattern of the finds showed how the land has been used, century by century.