I have just been shown an ariel photo of the field marked as Barcelona on the OS map. There is a large circle showing slap bang in the middle. According to the local historian (who lives not far from the site) a dig was done a few years ago and a ditch was discovered on the outside of the circle.
Looking at the field today nothing can be seen from the ground. Four fields away to the NW another settlement is marked on the map. Both are inside the area encircled by the Giants Hedge.