The Pool of Lucullus is a circular fishpond, so called because of a mistaken reading of a passage by Varro reporting that the gens Lucullia was known in Rome for building fish-farming facilities on the shores of seas and rivers.
It consists of two concentric rings linked by four asymmetrical arms, with two trapezoidal elements attached to the outside of the first ring. The whole fishpond is sunk into the ground and surrounded by an enclosure wall, probably built by Monsignor Calligola in 1721, which formed the so-called Garden of Paola.
The system, still working today, is fed by the outlet of Lake Paola through a slightly sloping channel fitted with regulating sluice gates, which supplies water to the side compartments; this is mixed with water from a sulphurous spring that rises from the floor at a temperature of 25°C.
The outer ring is interrupted by two openings; in the larger one there are three blind channels in which neckless amphorae are set in a row, perhaps used by the fish during spawning or as cool temporary hiding places in the hottest hours. Similar embedded amphorae are also found in the walls of the outer ring and in the trapezoidal compartments.
The central part, by contrast, seems to have been used for breeding oysters, given the horizontal beams suspended on supports. After all, the oysters of the Circeo, which grow in the coastal cavities and brackish lakes, were considered by the Romans the sweetest and most tender of all, as Pliny reports: “sed his –Circeiensibus ostreis- neque dulciora neque teneriora ulla esse compertum est”, that is, “it is known that nothing is sweeter or more tender than the oysters of the Circeo”.
In the Domitian period, perhaps at the same time as the construction of the imperial Villa at Palazzo, the fishpond was “restored” and its water supply modified, connecting it to the lake’s outlet.