The Olympic riding arenas are rubber mats ontop of gravel, the mats have a kind of pattern to the top (the riding surface, not the side down on the gravel).
They have a series of fairly deep square indentations all over their surfaces (they look a little like geogrid), then there is a mixture of textile fibers and sand ontop of the mats, sitting down in these square indentations.
Are there any arenas like this in the United States? Any in the midwest? This is supposed to be a popular product in Europe.
Has anyone here ridden on an arena like that? What are they like to ride on?
How are the edges of the mats kept aligned and closed, and the gravel kept from working its way to the top?
How does the surface work, with the square indentations and the sand/fiber mix top layer?