The lake is of glacial origin, formed by the retreat of the glaciers that once covered the Testa d'Arpy area.
The trail leading from this point is part of the extensive Alta Via 2 trekking network that spans the Aosta Valley.
The water in Lago d'Arpy is known for its intense emerald-to-deep-blue coloration due to high mineral content and depth.
The trailhead area is located just below the Colle San Carlo, a high mountain pass connecting Morgex and La Thuile.
The Inizio sentiero Lago d'Arpy marks the primary trailhead for reaching the glacial Lago d'Arpy, located at an elevation of 2,066 meters in the Aosta Valley. The route is a wide, unpaved forest road that transitions into a hiking path, accessible to families and casual hikers. The trail is approximately 3 kilometers long one-way with an elevation gain of roughly 200 meters. From the lake, visitors have direct views of the Grandes Jorasses and the Mont Blanc massif. The surrounding landscape consists of mixed coniferous forests, primarily spruce and larch, typical of the high-altitude Alps. The trailhead serves as a gateway to the Mont Colmet area and various high-altitude trekking routes.
The northern shore of the lake, looking back toward the reflection of the Grandes Jorasses peak in the water.
Bring trekking poles if you plan to continue past the lake toward the higher ridges for better stability on steep terrain.
Carry sufficient water, as there are no natural springs or services between the trailhead and the lake.
Use layers; temperatures at this altitude can drop rapidly even on sunny summer days.
Attempting the trail in late autumn or winter without snowshoes or proper winter hiking equipment, as the path is subject to heavy snow accumulation and ice.
The trail is best accessed from late June through early October; it is typically impassable or dangerous due to snow from November to May.
Practice Leave No Trace principles; keep dogs on a leash to protect local marmot populations and mountain fauna.
