This defense tower is an element of the Hohenstaufen fortification and was probably built around 1160. The "Bolander" secured the southwest side of the Ingelheim Palatinate and the “Rheingässer Gate”. An early pictorial representation of the hall area (name of the archaeological Zone Kaiserpfalz Ingelheim from early modern times) from 1545 by Sebastian Münster shows the original, multi-storey tower Loopholes and battlements (picture in the museum near the Kaiserpfalz). The name "Bolander" goes back to the noble family of the Lords of Bolanden, who acted as representatives of the kings on the Middle Rhine in the 12th and 13th centuries and maintained a customs office in the local Palatinate area until 1254.

Like many other wall and corner towers from the 12th to 14th centuries, the defense tower probably had a high entrance, which was Founding from the outside was only accessible via ladders. This could also be the case with the visible, bricked-up opening on the defensive wall Have acted at the Hochpforte. The wall thickness of the tower is considerable at 3.2 meters. Its interior has a diameter of 2.8 meters and is no longer accessible today.

Bolander defence tower