A tholos (pl. tholoi), from Ancient Greek θόλος), in Latintholus (pl. tholi), is an architectural feature that was used in the classical world. It is a round structure, usually built upon a couple of steps (a podium), with a ring of columns supporting a domed roof. It has been suggested that the tholos, well provided with water and drains, was where fish were sold, although other uses for the central tholos have been suggested, such as the place where official weights and measures were held for reference or as shrines to the gods of the market place. Some macella had a water fountain or water feature in the centre of their courtyard instead of a tholos structure.