There are two ancient hill forts in Porvoo, so-called small and big one. There is burial ground in a small hill from the Roman Iron Age (0-400 AD). The items found in excavations reveal that Porvoo river has been a remarkable trading centre already in prehistoric times and local people has had connections to Estonia and Latvia.
The bigger hill fort is one of the largest in Finland. It was used for defensive purposes already in the Viking Age (800-900 AD), but the fortifications date from the late 14th century. Today remains of double walls and dry moat are visible and restored.
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.