Tide mills are waterpower mills that take their energy not from a river but from the changing tides of the sea. Woodbridge mill is one of few that continue to make flour from tidal power. A mill was first recorded on the tidal estuary of the river Deben in 1170. The present mill building dates from 1793. The rising tide fills a 3-hectare mill pond to give a 2-metre fall of water at low tide. It is three storeys high and is built in the traditional local materials of timber with painted boards outside and a clay tile roof. It was restored and opened to the public in 1973 and is run by a charitable trust. Visitors see an introductory film on the ground floor and an interactive model showing how the mill works. The milling machinery is still in its traditional form, built of timber and cast iron, with four pairs of millstones.