Route de l'Hongrin is Switzerland's Secret Mountain Road Through a Military Zone

# Route de l'Hongrin: Switzerland's Best-Kept Mountain Secret

If you're hunting for one of Switzerland's most hidden gems, look no further than Route de l'Hongrin in the canton of Vaud. This is the kind of road that doesn't make it onto most travel itineraries—and that's exactly what makes it so special.

Stretching 24.3 km from La Lécherette to Corbeyrier, this mostly paved one-way route cuts through the Vaudois Alps like something out of a storybook. You'll wind past vineyards and light forests as you climb toward Les Agites pass (1,558m), where the road reaches its dramatic apex. Fair warning though: this isn't a leisurely Sunday drive. The ascent averages a brutal 9%, with sections hitting 20%+ gradients that'll have your palms sweating and your brakes working overtime.

The real star of the show is the Tunnel de les Agites (also called Tunnel de la Sarse)—a narrow, rough-hewn passage carved between 1938-1940 that feels like stepping back in time. There's barely any artificial lighting, just natural light trickling through cracks in the rock. Cyclists, take note: it's cramped and atmospheric in equal measure.

Here's the catch: the road runs through a military zone, so access is strictly limited. Summer months (July 15-August) offer the most freedom, though military ops might cause delays. Weekends and bank holidays have rigid one-way traffic schedules. Winter? Forget about it—the road closes entirely from November through May.

This is adventurous driving at its finest.