Walk from the public Aberarder car park beside Loch Laggan to Lochan a' Choire, surrounded by the cliffs of Coire Ardair, and return along the same path. Take the signed footpath left from the short entrance track, continue through the regenerating birch woodland past the Aberarder buildings, then follow the main glen path. Keep to the lochan route at the branches for the higher mountains. The outward walk climbs gradually, with a few steps and short steeper sections, before reaching the rocky lochan shore. Turn at the mapped path junction here and retrace the complete route to the car park.
The full return is about 12 km, with roughly 430 m of ascent; allow four and a half hours plus a margin for stops and changing weather. Gravel, stone and earth surfaces include loose stones, uneven ground and narrow sections. This is a mountain walk without shelter beyond the lower woods. Bring boots, warm and waterproof clothing, food, water, a map and compass, and the experience to use them.
Choose snow-free conditions and suitable mountain weather. Snow and ice, strong winds and winter avalanche conditions change the demands of this walk substantially; a missing avalanche forecast does not establish safe conditions. The route ends at the lochan and does not continue towards The Window, the scree slopes or the summits. Follow local notices and turn back if conditions or access are unsuitable. Keep dogs under close control and avoid disturbing wildlife.
Use the NatureScot visitor car park off the A86, with an invited parking contribution payable by card terminal or RingGo; check the current signs. A public toilet is beside the Aberarder buildings near the start. Carry what you need for the rest of the walk.
Route geometry: © OpenStreetMap contributors, licensed under ODbL. https://www.openstreetmap.org/copyright