The ruins located within the walls of Peel Castle are those of the former Cathedral of St German. Like the structures throughout the castle grounds, the cathedral's roof is completely missing. Robert Anderson examined the ruins to determine what repairs were required to restore the cathedral, and he reported to the island's Lieutenant Governor in 1877. However, none of the suggested repairs were carried out.
There is a pointed barrel-vaulted crypt below the chancel, measuring 10 × 5 × 3 metres, sloping to the entrance at the east. There is a cemetery in what was once the cathedral's nave.
References: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.