The structure of the arsenal consists of two large stone-built halls with vaulting supported by repeated pointed arches. The vaulting rests on ten piers, originally there were twenty two, the missing twelve and the structure they supported having been lost to centuries of coastal erosion. The main function of the arsenal was the building, repair and storage of warships. Amalfitan war-galleys were among the largest to be found in the Mediterranean during the Early Middle Ages.
The building now contains architectural and sculptural remains, a row-barge used in the Historical Regatta, a number of models of ships and it also acts as a venue for visual art exhibitions. Starting from December 2010, the Ancient Arsenals of Amalfi host the Compass Museum on the premises of the two aisles of the building, which were spared by the Amalfi seaquake of 1343.
Kakesbeck is one of the largest medieval fortifications in Münsterland and the oldest castle in Lüdinghausen. The imposingly grown complex originated in 1120 as a motte, a small hilltop tower castle. After numerous changes of ownership, the castle was extended onto two islands, but it was not until the 14th century that it underwent significant alterations and extensions under the von Oer family. The estate experienced its heyday in the middle of the 18th century, when it covered an area of almost one square kilometre and consisted of five further outer castles in addition to the core castle, which were secured by ramparts and moats.
The well-maintained condition of the castle today is thanks to the late Wilfried Grewing, the former lord of the castle. The foundation named after him has been particularly committed to preserving the property since 2020.