In the main square of Sibiu, Piata Mare, you will find some holes in the ground covered by a small, metal stopper, with a window to look through them. These are ancient grain silos. In medieval times, Sibiu was a fortified Saxon town. They spoke German, and the population had come from Germany to farm this great prairie. After harvest, grain was kept under the city; if the city was invaded, the residents would still have these hidden stores to keep them alive.