During testing of hydroacoustic equipment (sonar) conducted by the team of the Institute of Archaeology, University of Warsaw in the Lake Golenicko-Dobropolskie (NW Poland), an astounding archaeological relic was discovered by chance, i.e. resurrection-egg-shaped rattle (Polish pisanka). It is made of clay and richly decorated, i.a. with incised cross-shaped motives and punctured dots (Fig. 2, 3). The item was found sticking out of the ground on the surface of medieval stronghold, unknown so far, situated on the island in the western part of the lake (Fig. 1). Such rattles are dated to the time-span from 11th until 13th cent. They were quite popular in the Kievan Rus’ but also in the territory of Poland and – rarely – also in north-eastern Germany and southern Scandinavia. Great majority of egg-shaped rattles is glazed which is not the case of the described finding. However, it also differs from non-glazed ones as its ornament is much more elaborate than the others. Symbolic meaning of such finds is frequently connected with their apotropaic value but they are treated as symbols of new life and resurrection as well.