Ring wall

The ring wall is 2.10 m thick and encloses the complex with eight bends, most of whose buildings used it as a rear wall. Therefore, it is smoothly designed inwardly in the places where buildings adjoined, while on the rest and outwardly humped ashlars were used.^[6] The wall preserved in some sections up to a height of 5.50 m, but in no place up to the original height of the battlement at about 5.80 m above the ground level, which can be concluded from the connection points at the square keep.^[7]

Gate, chapel and rectangle keep

The gate building^[8] has a round-arched gate on the outside and an arcade with two arches on the inside. The gate hall extends over three bays. The columns stand on Attic-profiled bases and bear cubic capitals. Particularly noteworthy is the central one with the representation of an eagle. The southern vault dates from the 15_th century, while the northern one in principle dates from the time of construction.^[9] However, the vaults were removed and rebuilt in 1860.^[10] From the gate hall, a staircase led north into the palace. A keep with a rectangular ground plan on 11×12.10 m, which is still preserved to a height of 13 m, adjoins to the south. Originally, it was twice as high and its entrance was at a height of 7 m. The upper part was demolished in 1431, and replaced by a guardroom and a polygonal turret.^[11]

The chapel was placed directly above the gate hall, with an identical ground plan. In 1431 it was without a roof, but was repaired. In the 15th or 16th century, its eastern wall facing the courtyard was renewed with three round-arched windows. In 1764, the chapel was restored and then used by the inhabitants of the outer bailey for Protestant worship until 1811.^[12] After the demolition of the chapel in 1856, only few structural remains have overcome.^[13] Recognizable are the original five-tiered wall division and round-arched niches.^[14]

Palas

The Palas^[15] is located in the northern part of the palace and attached to the ring wall with its back wall. It had a floor area of 29×15.7 m. Above a low basement is a main floor, which was accessed from the courtyard via a representative, probably two-flight, open staircase. The representative facade facing the courtyard is probably the most impressive part of the complex. It is laid out asymmetrically, offset by 1.30 m, with 3+3 window axes on the western side and five window axes on the eastern side, each of which is bound together in arcades and designed internally with double columns. Their block capitals are decorated with plant motifs. Between the double group of three and the group of five windows is the entrance portal with a clover-shaped finial, lavishly decorated with vines. The "Barbarossa's head" walled in above it was placed there later, its origin unknown. The facade of the floor above is reconstructed differently in detail: thus, a large entrance window in the dimensions of the portal below is assumed^[16] or a double window.^[17] Of the remaining window arrangement, it is assumed that it repeated that of the floor below.

It is known from archaeological research that the basement had five rooms, all of which were accessed from a central room behind the entrance, which is still recognizable today as an arch. Based on the building connections – the interior construction was largely made of wood – it is assumed that the lower main level had a corridor behind the façade that provided access to the rooms on that floor. According to the window arrangement, two living rooms are supposed to have been located to the west, and a hall to the east.^[18] A mighty chimney remains here. The main hall is assumed to have been on the floor above. On the north side, integrated into the ring wall, there was a privy that could be used from both levels.^[19]

Round Keep

As the only free-standing structure of the complex, the foundations of a round keep can be found in the courtyard. This had walls 4 meters thick and a diameter of 16 meters. It is likely that it was never completed, as a structure of these dimensions was highly problematic in the soft subsoil,^[20] and the preserved foundations – unlike the tower at the gate – are still perfectly horizontal^[21] The foundations were only uncovered during an excavation in 1931.^[22] It has a carefully profiled plinth.^[23]

Additional buildings

Within the curtain wall were other buildings, but they are not been preserved:

• To the east of the palace a building adjoined, which existence's has been proven archaeologically^[24] and thought to have provided additional living quarters.
• Along the southern ring wall stood some more service and residential buildings.^[25]