OS Explorer is the Ordnance Survey's most detailed map and is recommended for anyone enjoying outdoor activities such as walking, horse riding and off-road cycling. The maps covers South Pembrokeshire on the west coast of Wales and can now be used in all weathers thanks to OS Explorer: an active, tough and versatile version . The OS Explorer Active range of OL maps now includes a digital version of the paper map, accessed through the OS smartphone app, OS Maps.