Two hundred and eleven cremation graves from the Roman Period and Early Migration Period, as well as nineteen other ancient features have been discovered at a heavily damaged cemetery of the Przeworsk Culture at Żdżarów in western Mazovia1. In the top part of grave 103, dated based on the presence of terra sigillata pottery from the Dicanus workshop in Pfaffenhofen from ca 230–260 AD, a poorly visible re-cut containing one clay vessel covered with a fragment of the bottom part of another was recorded (Fig. 1:a.b, 3); no human bones were found inside2. The vessels can be dated to the 14th–15th century, possibly even to the beginning of the 16th century. A different situation presents itself in the case of a cemetery of the Przeworsk Culture at Nadkole 2, in eastern Mazovia6. In addition to 157 graves from the Early Roman Period, clear traces of various modern cuts have been unearthed. The lower part of a cremation burial pit, probably from phase B2, was found under one of them. In the cut itself, fragments of four broken and incompletely preserved wheel-thrown vessels fired in a reducing atmosphere were discovered7. The pots that have been completely (Fig. 2:a.b) or partially (Fig. 2:d) reconstructed can be dated to the beginning or first half of the 16th century. Nevertheless, the end of the 18th century, or even the middle of the 19th century in rural areas, should be considered as the upper limit of occurrence of such potteryth. The fourth vessel is a very unevenly fired bowl, with a polished pattern on the inside (Fig. 2:c). This ornament indicates that it may have been tableware. This bowl should be dated to the 14th–15th century13 or later, assuming this chronology as its lower limit. An interpretation of both pottery assemblages described is not easy. In the case of Żdżarów, it seems possible to link the finds to child burials in clay vessels, known from the late Middle Ages and Modern period. Such graves, dating from the 14th to the 19th century, are known from several sites in Poland, almost exclusively in northern Mazovia15.16. The undoubtedly intentional burials at much older cemeteries, such as the four foetal burials in three vessels dating to 14th–15th century discovered at a Lusatian cemetery at Ożumiech, Przasnysz County19, are particularly interesting. No traces of bone were found in the Żdżarów vessel; however, as it was not possible to conduct specialist analyses of the fill at the time, it is not known whether it originally covered some form of burial or whether it was related to unspecified cult practices. The precise manner in which the vessel was dug into the top part of a much older grave pit (Fig. 3) shows not only the ritual character of the deposit itself, but also the ability to recognise a burial site abandoned a thousand years earlier. The archaeological context of the vessels from Nadkole suggests that they were a secondary deposit in the cut that destroyed the grave from phase B2 of the Roman Period29. In their case, there are no reasons to associate them with child burials or assign them a cult function; nor can they be considered a remnant of a late medieval or modern settlement, as no features from that period were discovered in the examined part of the site. The pottery published here shows that local populations from the late Middle Ages and Modern period either used (Żdżarów) or at least visited (Nadkole) much older cemeteries. This phenomenon is still very poorly researched, so every similar case requires a particularly thorough interpretation, based not only on a formal analysis of the feature itself and the pottery contained within, but also on the results of indispensable biochemical studies. It is worth noting that biochemical analyses of vessel contents conducted in Germany have recently confirmed the early modern custom of interring placentas (Nachgeburtsbestattung) in clay pots buried in the basements of homes27.