The former Roman Limes - Kapersburg Fort in the Taunus is one of the best preserved Roman military installations of the Upper German-Rhaetian Limes . It housed the Numerus Nidensium , an auxiliary force recruited from residents of the nearby Vicus Nida . The history of the castle has since the end of the 1st century, several construction and conversion phases and traces of a castellan . The fort was probably cleared without a fight shortly after the middle of the 3rd century as part of the Limesfall without a fight.