Lac de Derborence is a high mountain lake at an elevation of 1.465m (4,806ft) above the sea level, located in the Lizerne valley in the canton of Valais in Switzerland. It’s a narrow road with a long stretch of continuous hand crafted tunnels and windows with hairy 300m drop-offs.
The road to the lake is asphalted but very narrow. The paved road ends 500 metres from the lake, at the parking lot. There are some narrow sections -scarcely wide enough for two cars- where if two vehicles have to pass each other, one might have to reverse for some kilometers of winding narrow road to get to a place wide enough to pass. It shouldn’t be attempted by those who don't know how to reverse. Derborence inspired the Vaudois author Charles Ferdinand Ramuz to write a novel of the same name. The road is called Route de Derborence. It’s 10.7 km long winding its way into the valley, passing through exhilarating tunnels with windows in the rock. It’s an astonishing cliff road with lots and lots of tunnels. Truly amazing. There are two tunnel stretches, one is very long. But there are frequent openings with cliff views so it is never too dark. This is a truly stunning road, worth every hairpin corner and hairy 300m drop-offs off the side of the spectacular road to get to.
Located in the south side of the Bernese Alps, the narrow twisting road blasted out of a rock-face to the Switzerland’s youngest natural lake is usually impassable from May to October or November. Starting from the town of Vétroz, at 947m above the sea level, the ascent is 10.7km long. Over this distance the elevation gain is 518 meters. The average gradient is 4.84%, with some sections up to 8%. Closed to vehicles higher than 3.4m. Two huge landslides on 24 September 1714 and 23 June 1749 led to the formation of the lake, when an estimated 50 million m3 of rocks blocked the course of the Derbonne river. Lac de Derborence is known for its ecological diversity and plays host to some rare aquatic flora and fauna.