Several years ago, a Volhynian flint axe was found in a sand extraction pit located directly at the so-called Piwonin Lake, some 250 m south of the village of Piwonin, comm. Sobienie-Jeziory, distr. Otwock, woj. mazowieckie. The measurements are: reconstructed length – 142 mm, width of cutting edge – 52 mm, maximal thickness of the body – 17 mm. A flint ‘spearhead’ also comes from the vicinity, that is, from Sobieńki village. It is a projectile point made of Volhynian flint with the following measurements: length – 168 mm, width of the cutting edge – 53 mm, maximal thickness of the body – 15 mm, weight – 112.1 g. The appearance of both artefacts (axe and projectile point) can be viewed as remains of a non-ceramic grave or graves of the Mierzanowice Culture, which should be dated to the early phase of this culture (cf B. Bargieł, J. Libera 2005). Similar projectile point made of Volhynian flint constituted, apart from a nondescript axe and stone battle-axe which were lost, the furniture of the burial from Wola Wodyńska, distr. Siedlce (J. Przyborowski 1882, p. 190–191, fig. p. 190).