A massive Iron Age structure of wood and stone in an excellent state of preservation has been discovered on the banks of the Main River in Aschaffenburg, Germany. It dates to the 4th century B.C. The combination of the riverbank find location, the mixture of timber and stone construction and the early Iron Age date makes this a unique find.The first 10 wooden beams of the structure were discovered 26 feet beneath street level during civil engineering works on stormwater overflow basin in March 2026. The find was reported to the Bavarian State Office for Monument Preservation (BLfD) who followed up with archaeological excavation. The condition of the wood was so extraordinary that at first the BLfD team thought it was the remains early modern or even modern construction, but when the oak beams were analyzed in the dendrochronology laboratory of the state office, the tree rings were compared to known oak ring chronologies and found the beams came from trees felled in the 4th century B.C.Initial profiles already indicate that a large number of massive oak beams were incorporated into a structurally sophisticatedand likely also monumentaledifice, given that the structure terminated in a dry-stone wall facing the Main. Stone masonry is extremely rarely attested for the Iron Age. When stone structures from this period are documented, they typically constitute components of fortified complexessuch as timber-laced walls, explains Dr. Stefanie Berg, Head of the Department of Archaeological Heritage Conservation at the Bavarian State Office for Heritage Conservation (BLfD).The find site had already been cleared for construction under the mistaken belief that there was no known or suspected archaeological remains there. When the Iron Age structure was found, archaeologists had to scramble to get everything documented and recovered while working in less than ideal conditions at the bottom of a large, flat-sided pit 30 feet deep.An Early La Tne period settlement has long been hypothesized to have occupied the area of what is today Aschaffenburgs Old Town, but the kind of archaeological materials found thus far were small portable artifacts like fine jewelry and the occasional isolated architectural feature like postholes. This massive structure on the banks of the river is the first incontrovertible evidence of a permanent settlement from the La Tne period.Through archaeological excavation, documentation, and further investigations, researchers hope to gain new insights into the function of the complex as well as into the early settlement history of Aschaffenburg.