Water-driven floor mill

The remains of the second water-driven floor mill, in operation between 450 and 580 CE.
Top right the post-Herulian Wall. The slot-like structure is 5m long and 4m deep. The channel
(bottom right) carried the water necessary to run the wheel, which resolved in the slot or race.
The wheel was of the ‘overshoot’ type. For a description of such a mill, see Vitruvius 10.4 - 5.