Plan Incliné de Ronquières Wallonia

This 1.4km-long slope, or 'sliding lock', at Ronquières is a curious 1968 contraption that lowers boats down a steepish gradient in a giant bathtub. It’s strangely mesmerising to watch it trundling oh-so-slowly into action. The two-hour visit includes a 3D film and views from the top.