A good arena starts with a firm but forgiving base—rubber‑filled sand or a cork mix gives the right grip without crushing the hooves. Keep the surface level and free of sudden bumps; use a light, even grain to reduce slippage. The arena should be at least 20 metres wide and 30 metres long for most riders, giving plenty of room to swing out and recover. Place the walls high enough that the horses can see and feel the boundary but low enough to keep the riders from feeling trapped—about 1.5 to 2 metres works well. Add a shallow border of a softer material, like a rubber mat, around the perimeter so the horse’s feet aren’t exposed to hard concrete. Finally, keep the footing clean and dry; a regular sweep and slight top dressing with fresh sand or turf will keep the footing safe and give riders confidence.