Hesselbach Castle was originally a Roman fortress of the older Odenwald line of the Neckar-Odenwald Limes. The present-day archaeological site is located in the area of Hesselbach, a district of the city of Oberzent in Odenwaldkreis, Germany. The former fortification is the most thoroughly researched military camp of the Odenwald Limes and the southernmost Limes fortress in Hesse. The Hesselbach fortress serves as a "reference fortress" for almost all other military camps of the Odenwald Limes; the insights gained here are used in Provincial Roman Archaeology to interpret the entire Limes section between the Main and Neckar rivers.