OS Explorer map OL 50 shows Loch Ericht, Loch Laggan & 16 of the surrounding Munros, as well as part of the Cairngorms National Park. This map replaces the previous OS Explorer map 393 for this area. With this map you will receive a code for use on your i OS or Android smartphone or tablet. Find our more at Mobile Download FAQ. The town of Dalwhinnie is the base for this area, & aside from the A86 & A9, there is no road access to most of this region. The OS Explorer map for Ben Alder, Loch Ericht & Loch Laggan is available in both the standard paper version & weatherproof ' Active' version.