Within the urban fabric of Obernburg am Main, the Römermuseum Obernburg plays a central role: it primarily houses finds from the Kastell Obernburg and its associated civilian settlement. The museum is located at Untere Wallstraße 29a, below the old town and close to the River Main.
Archaeological work between 2000 and 2007, in particular the excavation of a beneficiarii station with numerous new votive inscriptions, made the spatial limits of the museum apparent. Consequently, the museum development plan envisaged an expansion into a supraregional institution, linked to the inscription of the Upper Germanic-Rhaetian Limes on the UNESCO World Heritage List. The intention was to develop the museum into the Bavarian central museum for the Mainlimes and aspects of Roman law; in 2007 the city council approved a feasibility study and the formation of a planning group for a "Mainlimes Central Museum." However, planning was halted in 2009; central points of dispute were funding and the anticipated economic effects. Subsequent significant finds are now likely to be displayed in Munich or at another fort site on the Main. A citizens' referendum on 27 September 2009 rejected the continuation of the plans by 64.97%.
The permanent exhibition begins with a town model that explains the Roman topography and development of Obernburg. On the ground floor a substantial stone collection dominates, featuring inscriptions of the beneficiarii consulares, the building inscription from the staff building of the cohort fort, and fragments of Jupiter–giant columns; a reconstructed column stands in front of the museum. A group of inscriptions records deployments of vexillationes of Legio XXII Primigenia from Mainz as "in lignariis" employed lumbering detachments and documents the military use of the Spessart, the Odenwald and the Main (possibly the Mümling). In the basement a Mithras stone is displayed with a reconstructed mithraeum; on the mezzanine gravestones and votive stones illustrate the cult of gods and the dead. The upper floor presents small finds such as tools, fibulae, cosmetic and medical instruments, everyday pottery and coins. Notable is a glazed bowl from the 4th century AD, which by its decoration is considered one of the region's earliest Christian testimonies. Another room is available for temporary exhibitions.