The active explorer ol 39 is a detailed weatherproof map which covers the northern area of loch lomond and the towns of tyndrum ardlui crainlarich and arrochar a replacement for the previous os explorer map 364 for this area the ol 39 allows you to indulge in the stunning scenery and covers one of the most popular munros ben lomondcolour swatchorangebrandordnance surveycolourorange