Roman Castle Kleiner Feldberg

The rectangular fort, with dimensions of 78 by 93 meters, had an area of just over 0.7 hectares. The defensive wall was constructed from irregular, mortared ashlar stones, then plastered and given a red faux joint paint finish. The wall was surrounded by a simple pointed ditch, and all four rounded corners of the wall were equipped with watchtowers. Inside the wall was the agger, an earthen rampart that served as a wall-walk. The camp was oriented with the Porta praetoria (main gate) to the northwest, where the Limes passed the camp at a distance of approximately 100 m. All four gates were fortified with double towers.

Within its fortified square, the Feldbergkastell enclosed several masonry buildings, including the Fahnenheiligtum (Aedes) of the centrally located Principia (headquarters building) and a Horreum (granary) in the west, as well as another stone building east of the headquarters building, which may be identified as the Praetorium (commander's residence). However, most of the buildings inside the camp consisted of wood and half-timbered constructions and are no longer preserved. The troops were housed in such a building in the southern quarter, with various workshops and stables in the northern quarter. Further foundations along the cross street may have served to terrace the sloping terrain. In addition, wells and cisterns were present. Hair fragments of a large bronze, dating to around 230 AD, originate from the fort area.

Outside the actual fort, towards the Limes, was the fort's bathhouse. The foundations of this balineum were restored as part of the restoration measures carried out in 2004/2005. The water supply for the soldiers' thermal baths was provided by wooden pipe lines, which could be identified by wooden pipe rings, from the nearby Weil spring.

The Vicus (civilian settlement) belonging to the fort, with the soldiers' family members and Romanized locals, was located in two separate settlement cores southwest and southeast of the defensive structure, along the roads leading from the respective gates. It consisted mainly of elongated and densely built houses. Agriculture was not possible in this area due to unfavorable climatic and soil conditions. In addition to artisanal services for the fort, the inhabitants probably mainly engaged in trade, livestock farming, hunting, and logging. Today, no remains of the Vicus are visible. A cemetery could be located southwest of the fort.

The Limes from the Kleiner Feldberg fort to the neighboring Saalburg in the east has been very well preserved due to its secluded location in the Taunus forests; for many kilometers, the course of the rampart and ditch can be followed. Here are also some smaller Limes structures, some of which have been preserved in their foundations, or at least are perceptible in the terrain. Among them is the small fort Altes Jagdhaus, a single-gated stone fort from the mid-2nd century, approximately 630 square meters in size.

The source of the Weil is located 200 m southeast of the fort, uphill in the spruce forest. The relic of a wooden water pipe (Deuchel) found on site was dated to approximately 170 AD using dendrochronology.

The Romans reached the Limes fort via the Feldbergstraße, the so-called Pflasterweg (Paved Path), a connection over the Taunus ridge to Fuchstanz, past the Altkönig slope (Haderweg) over the Hünerwiese and then over the Stierstädter Gemarkung to Niederursel to the Saalburgstraße, which left Roman Nida at the north gate.

The Reifenberger Wiesen, designated as a nature reserve northwest of the fort, are the highest of their kind in the Taunus. In Roman times, these were pastures for the supply of the Vicus. Today, they form habitats for 183 different useful, medicinal, and flowering plants, as well as ferns. Typical plants include milkworts and rockroses, originally native to the Mediterranean region, eared willow and Carpathian birch in damp areas; in early summer, the yellow of winged broom and arnica dominates. From the hiking trail between Feldbergkastell and the Rotes Kreuz parking lot, a wide view of Oberreifenberg with its castle ruins opens up over these meadows.

Foundations of a glassworks from the first half of the 15th century are located about 1 km steeply downhill southeast of the pass on the valley floor of the Emsbach. According to excavation findings, the 300 m² area contained a main and four secondary kilns as masonry dome structures. For the Middle Ages, typical green utility glass, called Waldglas (forest glass) due to its production conditions and iron oxide content, was manufactured. This economic-historical component is still preserved in the place name of Glashütten, which is only 1.5 km away from here.