Roman fishponds are artificially created pools of fresh or sea water constructed for the purpose of cultivating, breeding, and/or storing fish. Water enters and leaves the pond by means of a series of channels and pipes, the flow of water being controlled by one or more sluices and overflow channels. Roman fishponds were dug into the ground and lined with stone; they are either square or rectangular, about 30m by 10m, and are usually associated with major villas.
Roman fishponds are generally located from excavation, but they may be recognised as field monuments through earthworks or as cropmarks through aerial photographs. Positive identification often requires excavation.
Roman fishponds and the individual components that comprise them are frequently confused with other classes of monuments, especially those which also involve water management, for example ornamental ponds and bathing ponds. In all cases, the classification of the monument as a Roman fishpond relies on the careful examination of the arrangement of the main components represented and its relationship to other features.
Specifically excluded from this definition of Roman fishponds are all other kinds of ponds and water-filled features which may have been used to hold fish but which were not specifically constructed for that purpose, such as ornamental and bathing ponds. Roman fishponds which form components of other monuments such as villas are also excluded from this definition.
Roman fishponds were constructed for the management of fish stocks in order to provide a constant and sustainable supply for food. As such, Roman fishponds were probably a very valuable resource.