In the early Middle Ages the Hesselberg region was part of the king's forests. Sparse castle ruins are found on Ehinger mountain and on Schlössleinsbuck. The construction on Ehinger mountain has its seeds in the Carolingian-Ottonian period (8th-9th centuries). Tombs discovered there point towards a violent end caused by Hungarian soldiers at the end of the 10th century when the Hungarians burnt down the whole castle. The building on Schlössleinsbuck was originally intended for use as a refuge, in the 11th or 12th century it was expanded by the lords of Lentersheim and adapted as a well-fortified knight's castle. The castle's destruction is related in the family tree of the lords of Lentersheim: When Conrad of Lentersheim returned from the northern Italian campaigns of king Frederick II. in 1246, his castle was completely destroyed. Thereupon he began building a new castle in Neuenmuhr. In fact, soldiers from the Hesselberg region accompanied the mentioned Hohenstaufen king Frederick II to Italy in 1239 in order to fight against pope Gregory IX. Until they died off at the beginning 19th century, the lords of Lentersheim lived at their castles in Alten- and Neuenmuhr, today's Muhr am See. After this direct colonisation of Hesselberg ended.