Maybe something at http://wiki.openstreetmap.org/wiki/Riding will help. I tried to tag a pack station in the Sierra Nevada and asked for help on the tagging list last year with less success than I'd hoped, possibly due to my lack of equestrian knowledge. But it did seem It seemed to me that the western US concept of equestrian facilities did not map into the British scheme of things. Since you are asking about a corral I wonder if that might happen for you too. I suspect that corral would be translated to paddock with the suggested tagging being landuse=animal_keeping, animal_keeping=horse, animal_keeping:type=paddock

Maybe something at http://wiki.openstreetmap.org/wiki/Riding will help. I tried to tag a pack station in the Sierra Nevada and asked for help on the tagging list last year with less success than I'd hoped, possibly due to my lack of equestrian knowledge. But it did seem to me that the western US concept of equestrian facilities did not map into the British scheme of things. Since you are asking about a corral I wonder if that might happen for you too. I suspect that corral would be translated to paddock with the suggested tagging being landuse=animal_keeping, animal_keeping=horse, animal_keeping:type=paddock