The swings in cities are metal and plastic, in rural areas they are made with logs. Our log ones last much longer and are not naughty for the planet when they eventually break. The roundabouts are far fewer in the countryside, often those token ones that everyone just drives straight over and are largely pointless. We have ups and downs as well but they are a little more complicated to describeSorry but these swings and roundabouts you mention, are they in the city's or rural areas?