Posted: 24/09/2013 at 15:02
It may have foundations or a membrane underneath, if it's been made properly. They can be very expensive to make. There may not be topsoil underneath. There may be hardcore even. Have you dug down? The bark alone will not be suitable for most plants. I have horses and I can't help feeling it's a shame to get rid of something that most riders would give an arm and a leg for. I am also a keen gardener.
Also the correct name is manege. It is a French word and menage means "housework", not an arena! They constantly get it wrong on programmes like "Escape to the Country". A real manege should be a covered arena.