Poilvache Castle is a ruined medieval castle in the Walloon municipality of Yvoir, overlooking the village of Houx from a clifftop on the river Meuse.
The present ruins date from the 15th century, although there has been a fortification on the site since the time of Charlemagne. The Liégeois town of Poilvache, a thriving walled town, protected by a castle, with a prosperous economy and its own mint, and allied to Duke Philippe the Good, virtually ceased to exist following its 1430 siege by the rebellious Prince-Bishop of Liège, Jean de Heynsbergh, and an estimated army of 30,000 Liégeois, Dinantais and Hutois. The Dinantais besiege Montaigle Castle in 1465 for the same reasons but Montaigle was destroyed in the 16th century by the army of Henri II of France.
From the top of these rocks it is possible to see the isle in the river where the German army and its armoured divisions crossed (in the North of the isle), the river Meuse on 13 May 1940.
References:The Walls of Constantinople are a series of defensive stone walls that have surrounded and protected the city of Constantinople (today Istanbul) since its founding as the new capital of the Roman Empire by Constantine the Great. With numerous additions and modifications during their history, they were the last great fortification system of antiquity, and one of the most complex and elaborate systems ever built. They were also the largest and strongest fortification in both the ancient and medieval world.
Initially built by Constantine the Great, the walls surrounded the new city on all sides, protecting it against attack from both sea and land. As the city grew, the famous double line of the Theodosian Walls was built in the 5th century. Although the other sections of the walls were less elaborate, they were, when well-manned, almost impregnable for any medieval besieger.