interesting idea: plant box and belts . Hook together several belts to be large enough to go around if using real leather belts (from thrift store) . these "belts" look more like strap webbing and could be DIY made to size.
Granite Setts are incredibly hard wearing, making them a great choice for high traffic areas such as pathways like in this garden pathway design by Thorburn Landscapes. Nice design to use for narrow patio area outside french windows.