The lifts on the old Canal du Centre are a series of four hydraulic boat lifts near the town of La Louvière, classified both as Wallonia"s Major Heritage and as a World Heritage Site. Along a particular 7km stretch of the Canal du Centre, which connects the river basins of the Meuse and the Scheldt, the water level rises by 66.2 metres. To overcome this difference, the 15.4-metre lift at Houdeng-Goegnies was opened in 1888, and the other three lifts, each with a 16.93 metres rise, opened in 1917. These lifts were designed by Edwin Clark of the British company Clark, Stansfield & Clark.
The lifts were part of the inspiration behind the Peterborough and Kirkfield Lift Locks in Canada. In the late 19th century Richard Birdsall Rogers visited the locks as to understand and study possible ideas for a lift lock system.
These industrial monuments were designated by UNESCO as a World Heritage Site in 1998. Of the eight hydraulic lift locks built in the late 19th and early 20th century, the four of the Canal du Centre are the only ones still functioning in their original form.
Since 2002, operation of the lifts has been limited to recreational use. Commercial traffic now bypasses the old lifts and is handled by the enormous Strépy-Thieu boat lift, whose rise of 73m was the highest in the world upon completion.
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.