Ordnance Survey Maps. We stock a selection of Ordnance Survey Explorer Outdoor Leisure Maps online, covering National Parks and other popular walking areas. We also stock a wider range of Ordnance Survey Landranger, Explorer and Outdoor Leisure Maps and Harvey's Maps at our Bourne End Store. If you are a group or organisation wishing to purchase a number of maps please contact our group sales department on 01296 663848 and we can source them for you.