Rietburg Castle, which has been documented since the beginning of the 12th century, was probably initially a fief of the Bishop of Speyer to the nobles of Rietberg, who are documented under this name from 1204. The castle's heyday lasted from the 13th to the 15th century, during which time it was named one of the "most excellent fortresses" of the Speyer church. In 1460, the castle was captured by troops of the Counts of Leiningen during the so-called Electoral Feud. As early as 1472, the castle's own St Catherine's Chapel was moved to Marientraut Castle because the castle was only being used in a rudimentary way. From then on, the castle began to decline. In 1552, the henchmen of Margrave Albrecht Alkibiades seized the castle. The "coin treasure" of almost 600 silver coins, which was discovered in 1872 and has since disappeared again, also dates from this time. There is no exact date of destruction, but the castle appears to have been in ruins as early as 1681. In 1822, the municipality of Rhodt acquired the ruins together with the surrounding forest. In 1846, the castle was revitalised with the construction of Villa Ludwigshöhe, as King Ludwig I and the royal family regularly visited the castle during their summer stays, which made the ruins famous throughout the region. From 1872, the Rietburg was uncovered by the Edenkoben Canton Beautification Association, the first of its kind in the entire Palatinate, as part of patriotic sentiment and rebuilt according to the ideas of the time. This laid the foundation stone for the castle ruins as a unique vantage point in the Southern Palatinate and a tourist monument to this day.
Various layers of walls and individual stones indicate that construction began towards the end of the 12th century. The ring roughly circumscribes a trapezoid. In the north-west corner is the higher main castle with a mighty shield wall, three metres thick at ground level, which rises up to fourteen metres high like a tower at the southern end and is clad with humpback ashlars. Terraces and modern additions mar the appearance of the castle. Only the curtain wall and the gate have survived from the lower castle. Originally, the castle was probably whitewashed. The shield wall that dominates the scene today was probably built around 1260 from the remains of an older castle that had previously been destroyed and is now only visible in rudimentary form. The later added caponier could have been built in the 15th century as a platform for a firearm. Otherwise, the castle's current appearance is characterised by the unhistorical restoration work carried out from 1872 onwards, although this was based on surviving ground plans and foundations. The destroyed bridge over the western neck moat was replaced by a new bridge in 2012 by the Rietburgverein. Finally, in 1930, a hut was built by the Palatinate Forest Association as a precursor to the high-altitude restaurant built in 1954-1957.
The historical highlight of Rietburg Castle is the abduction of Queen Elisabeth of Brunswick to Rietburg Castle in 1255 by Hermann von Rietberg. She was the wife of the Roman-German King William of Holland, who, supported by the Pope, put an end to the rule of the Hohenstaufen dynasty over the Roman Empire of the German Nation. For a long time, this act was attributed to rapacity and the loyalty of the Rietbergers to the Hohenstaufen dynasty. According to the latest findings, it was not the queen but her companion Adolf von Waldeck, the imperial court judge and powerful deputy of the king, who was the target of the abduction. On behalf of the king, von Waldeck maintained close relations with the Rhenish League of Cities, an association of many German cities that opposed the rights of the knights, who were mainly of lower nobility, in their endeavours for free trade and the expansion of their position of power. This resulted in numerous violent conflicts, of which the kidnapping of the queen and the imperial court judge was probably the climax of the dispute. Hermann von Rietberg was presumably pursuing political goals with other regional knights. A powerful alliance of towns and princes then besieged and destroyed Rietburg Castle. The shield wall was built from the remains of the destroyed castle around 1260, which explains the use of reworked humpback ashlars and the irregular course of the rows of stones.