At around 7,300 feet in the southern French Alps sits Lake Allos, the largest natural high-elevation lake in Europe. It spreads across roughly 54 hectares — over 2,000 feet across and more than 3,000 feet long — on the western edge of Mercantour National Park, ringed by larch forest, wildflower meadows and jagged peaks.
Despite the altitude, it's a surprisingly accessible outing. From the parking area at Laus, about 20 minutes' drive outside the town of Allos, the walk in takes one to two hours round trip with only about 790 feet of climbing. The most popular route follows a stream, climbs rock-carved steps and crosses open valley before the lake comes into view.
Once there, the water is the headline act. Fed almost entirely by snowmelt and low in oxygen, it's remarkably clear, often mirroring the surrounding mountains. Mont Pelat, the tallest summit in the valley, rises just 2,700 feet above the lake's surface, and wildlife watchers have a decent shot at spotting ibex and chamois on the slopes.
A seasonal mountain refuge opens beside the lake in summer, serving hearty home-cooked food on lakeside terraces and offering dorm beds for hikers stretching the trip into a multi-day trek. In winter the lake is effectively off-limits to anyone but experienced mountaineers, so this is a warm-seasons destination.
Beyond the lake itself, Mercantour rewards effort. A 6.8-mile trail loops past several smaller glacial lakes northwest of Allos, while the tougher ascent of Mont Pelat runs about 8.3 miles over knife-edge ridges — on a clear day the views reportedly reach as far as Mont Blanc to the north.
Reaching the trailhead means a drive of just over two hours from Nice Côte d'Azur Airport, France's second-busiest after Paris. That makes Lake Allos an easy add-on to a Riviera trip: a morning flight into Nice, an afternoon in the mountains, and an overnight in a refuge above 7,000 feet.
Why it matters: most visitors to the south of France stick to the coast. This is the counter-programme — genuine high-Alpine scenery, wildlife and crystalline water, reachable on a moderate day hike from a major international airport.
