Nonnebakken (literally, "Nun Hill") is the site of one of Denmark's six former Viking ring castles, built during the reign of Sweyn Forkbeard, who had forced his father Harold Bluetooth to leave the country and seek refuge by the Jomsvikingson Wollin (modern Poland) around 975. The fort enabled its occupier command of the Odense River passing next to the hill.
The name refers to the Benedictine Nunnery located on the site at earlier times. To the end of the 12th century the Nuns left the site to build a new Church in Dalum to the southeast, now a suburb of Odense.
The earthworks can still be recognized in the panorama of Odense in the 'Civitates Orbis Terrarum' from Georg Braun and Frans Hogenberg. The engraving is in volume 5, that was finished in 1598 (although first published in 1612-18 in Cologne), on plate 30, that was made in 1593 from information contributed by Heinrich Rantzau or from sketches he gave in order. It also appears on the panorama of Odense published by Braunius in 1593.
The archaeological remains of the fort took heavy damage when a building for the Odd Fellow lodge was constructed on the site during the late nineteenth century. The site was excavated by the Fyns Stiftsmuseum. The castle had a diameter of 120 m and dates to 980-1000, similar to the other Viking ring castles.
Although finds have been reported from 1775 and 1889 the extent of the whole structure was first determined in 1953. The next major gain in Information was when in 1988 trenches where dug for laying cables. A ditch with pointed bottom was observed during the excavations. It was at least four meters wide and two meters deep with a berm of maximal 10 to 12 meters. The later filling could be dated to the time of the abbey. The profile of a ditch with pointed bottom eight meters wide and some four meters deep was excavated in the northeast and the northwest. During excavations prior to larger diggings for heating pipes in 1995/97/98 a ditch eleven meters wide and three meters deep was observed. A spade made of oak was found that was dated with dendrochronology to the functioning time of the structure. Excavations in 2002 revealed parts of the abbey.References:
The moated castle at Beersel is one of the few exceptionally well-preserved examples of medieval fortifications in Belgium. It remains pretty much as it must have appeared in the 15th century. Remarkably, it was never converted into a fortified mansion. A visitor is able to experience at first-hand how it must have felt to live in a heavily fortified castle in the Middle Ages.
The castle was built in around 1420 as a means of defence on the outer reaches of Brussels. The tall, dense walls and towers were intended to hold any besiegers at bay. The moat and the marshy ground along its eastern, southern and western edges made any attack a formidable proposition. For that reason, any attackers would have chosen its weaker northern defences where the castle adjoins higher lying ground. But the castle was only taken and destroyed on one occasion in 1489, by the inhabitants of Brussels who were in rebellion against Maximilian of Austria.
After being stormed and plundered by the rebels it was partially rebuilt. The pointed roofs and stepped gables are features which have survived this period. The reconstruction explains why two periods can be identified in the fabric of the edifice, particularly on the outside.
The red Brabant sandstone surrounds of the embrasures, now more or less all bricked up, are characteristic of the 15th century. The other embrasures, edged with white sandstone, date from the end of the 15th century. They were intended for setting up the artillery fire. The merlons too are in white sandstone. The year 1617 can be clearly seen in the foundation support on the first tower. This refers to restorations carried out at the time by the Arenberg family.
Nowadays, the castle is dominated by three massive towers. The means of defence follow the classic pattern: a wide, deep moat surrounding the castle, a drawbridge, merlons on the towers, embrasures in the walls and in the towers, at more or less regular intervals, and machiolations. Circular, projecting towers ensured that attacks from the side could be thwarted. If the enemy were to penetrate the outer wall, each tower could be defended from embrasures facing onto the inner courtyard.
The second and third towers are flanked by watchtowers from which shots could be fired directly below. Between the second and third tower are two openings in the walkway on the wall. It is not clear what these were used for. Were these holes used for the disposing of rubbish, or escape routes. The windows on the exterior are narrow and low. All light entering comes from the interior. The few larger windows on the exterior date from a later period. It is most probable that the third tower - the highest - was used as a watchtower.