Four successive military installations, three earth camps and a stone fort were found above the Roman settlement (vicus) on the crest of the Heidenberg between Kastellstrasse and Platter Strasse. The three earth camps are relatively, but not absolutely, chronologically dated. There is no evidence of the inner buildings, which were certainly made of wood, or of the units stationed here.

The stone fort was built in 83 AD after Domitian's Chattian War for a 500-man unit and remained occupied until the 1930s. It was oriented to the east, so that the lower lying vicus could be easily overlooked from the camp area. In addition, the view from here extended as far north as the Taunus, as far west as the Rheingau and as far south as the Rhine and Mainz.

The Roman fort, with an almost square ground plan, has some special features compared to the familiar military architecture on the terrain that slopes steeply to the southwest and southeast. It was protected on at least three sides by two ditches, 10 and 7 m wide respectively, which were only not cut in the Röderstraße on the steep slope towards the Nero valley. Presumably, wooden bridges resting on retaining walls made it possible to cross the ditch. The walls were probably around 3.8 m high and were covered with 1.6 m high tin covers made of red sandstone. Particularly in the area of the four gates, the outer front of the defensive wall appears to have been more carefully constructed with small hand ashlars made of Mainz limestone. The entrances, which varied in width and were flanked by two towers attached to the inside of the defensive wall, were located almost in the middle of the fort's front. Between the corner and gate towers, there were two 4.71 m wide intermediate towers on all sides at different distances from each other, which probably also housed the staircases leading to the battlements. While only a well-preserved hearth was found in the front area of the timber-framed crew barracks, the stone buildings in the lateral area could be examined in their entirety.

Behind the centrally located main building (principia), around a third of the scamnum (area) remained undeveloped. The courtyard with a water basin was adjoined at the rear by five rooms, the middle of which served as a flag sanctuary. Statues of Roman emperors must have stood on the five pedestals in front of it. To the right of the principia were two buildings that were probably used as storehouses (horrea) and the commander's residence (praetorium), which was rebuilt several times. However, the interpretation of two smaller buildings erected behind it as stables remains less certain. For a four-winged building between the commander's residence and the left side gate (porta principalis sinistra), the term workshop (fabrica) has become established.

The Roman fort will have been finally vacated by the time a larger administrative unit, the so-called civitas, was founded in the 2nd century at the latest. We do not know whether the abandoned site remained in fiscal ownership as a military area, but further state use by the army cannot be ruled out, especially as it was not built over at a later date.