Bents Green Special Schools provide education for learners with special needs. It is first recorded as a school on the 1935 25 inch OS map. The school is then marked as an 'Open Air School'. These were schools for 'delicate children' where it was thought that exposure to the open air would nourish them. The polygon marks out an area containing the playing fields as separate from the school buildings. The patterns depicted on the 1st Edition OS map of 1855 suggest the area had been included in the Upper Hallam enclosure award of 1805. The origin of the moorland landscape is uncertain though this area is likely to be moorland by the Roman period (see Bevan 2003 for discussion of environmental evidence). Legibility is invisible