An archaeological investigation was carried out during work undertaken by the local council of Pisogne to rearrange piazza Umberto I and the area between corso Giuseppe Zanardelli and the railway. In the medieval period the area occupied by the piazza was largely submerged by the lake. The western part of the piazza is the result of the reconstruction undertaken in 1817, whilst a portion of the area between corso G. Zanardelli and the railway was built upon when the latter was constructed in 1907. In the eastern strip two stretches of the piazza’s paving composed of gravel and cobbles came to light. Also revealed were the remains of the circular base dating to 1817 on which stood the statue of S. Costanzo, patron of Pisogne. Below a layer of grayish black sandy silt an alignment of 10 millstones (diam. 1 m, height 0,20 m) was uncovered. Worn and damaged by use they were re-used in this position. Presumably, this feature continued to the north, where it was cut by in antiquity by the trench for a small channel, whilst to the south it ends up against a compact surface of black loam, cobbles and gravel. The underlying stratigraphy shows that the alignment of the millstones follows the line of an earlier border. At about 0,20 cm further down a structure of porous tufa stone blocks emerged on the same alignment. Both the alignment of millstones and that of the stone blocks end to the south with a right angle towards the west. Along the western edge of the alignment a few fragments of wood were uncovered, probably relating to a series of piles that must have supported the harbour wharf constituted by the alignment of blocks and overlying millstones. A Venetian coin dating to between the 17th and 18th century was found in the layer of silt covering the wharf. It is certain that it was abandoned in 1797, the year in which Cesare Barilli made the drawing of piazza del Mercato which attests a more advanced coastline. (Viviana Fausti)