Kind of hard to clearly describe without pictures :)
The premise is a moving floor powered by water - the floor is the top of a large, rough roller powered by water (it could be magic if desired, but I think it can be done with medieval technology.). The floor is not flat but curved (the larger the roller, the less obvious the curve) Go to Comment
A rich southern landowner once imported hundreds of thousands of spiders and distributed them along his long, tree-lined road. After a couple of days, when the spiders had make an incredible number of webs amongst the rows of trees, he spread fine gold and silver dust on them to create a spectacular shimmering view. (true story) It was for his daughter's wedding day.