The foundations of a Roman-era burial mound with stone walls have been unearthed near Nassenfels in Upper Bavaria. Stone circular constructions like this are extremely rare finds in what was then the Roman province of Raetia.It was discovered last fall during construction work to build a stormwater retention basin near the town of Wolkertshofen. Because the site was known to have remains of settlements and burials going back to the Neolithic, the work was overseen by archaeologists in collaboration with the Bavarian State Office for Monument Preservation.The excavation first only returned fragmentary remains from the Neolithic settlement, but then a circle with an outer diameter of 12 meters (39.4 feet) made of carefully arranged stones emerged. On the south side of the circle, an extension two meters (6.6 feet) square also made of stones was found. This was likely a foundation for a funerary monument, perhaps a stele, statue or altar.The quality of the construction, the Mediterranean style of the stone base of the walls, and the location alongside the Via Claudia Augusta, the major Roman road that crossed the Alps linking the Po valley of northern Italy to Augusta Vindelicorum (present-day Augsburg), indicates this was a burial tumulus from the Roman period. The remains of a large Roman villa rustica (country estate) were unearthed less than two miles away in 1993, which also supports the identification of the structure as a funerary mound since the wealthy landowners would have been able to afford such high-end construction.No human remains or grave goods were found within the circle, however. Archaeologists believe it may have been a cenotaph, a tomb without burial that memorialized someone who died elsewhere. These monuments were dedicated to highly-regarded individuals who were commemorated in such a prominent way to enhance the prestige of the family or community.Raetia encompassed parts of modern Switzerland, Northern Italy, Austria, southern Germany and all of Liechtenstein, where there was a long tradition of burial mounds going back to the Bronze Age. In Raetia, prehistoric burial mounds were often reused for secondary burials in the Iron Age. Roman tumuli began to appear in the Augsburg area in the 1st century, and may have been a deliberate return to the areas pre-Roman cultural tradition of burial mound construction, but tumuli with stone ring walls of monumental proportions are connected to Roman funerary custom rather than the earlier Celtic practices.Its size, quality and preservation make the Wolkertshofen burial mound unique in the region, shedding new light on the funerary and memorial practices of Roman Raetia.