Passo Castrin: The Alpine pass hidden inside a tunnel
Passo Castrin (also known as Hofmahdjoch) is a high-mountain pass reaching an elevation of 1,781m (5,843ft) above sea level in the Autonomous Province of Bolzano, South Tyrol, Italy. Located in the Ortler Alps, this pass is unique because its highest point is actually situated at the south entrance of a tunnel built in 1998.
| Road facts: Passo Castrin (Hofmahdjoch) | |
|---|---|
| Location | South Tyrol, Italy (Ortler Alps) |
| Length | 17 km (10.56 miles) |
| Max Gradient | 19.0% |
| Elevation | 1,781 m (5,843 ft) |
| Road Name | Strada Provinciale 86 (SP-86) |
Where is the road to Passo Castrin?
The road across the pass, officially designated as Strada Provinciale 86 (SP-86), connects the villages of Laurein and Santa Valburga. This 17 km journey through the northern part of Italy is a relatively modern link, significantly improved by the construction of the tunnel system in the late 90s, which allows for better access through the rugged Ortler Alps.
How steep is the drive to Hofmahdjoch?
Don't let the "good condition" of the pavement fool you. The road is incredibly steep, with some ramps hitting a maximum gradient of 19.0%. It is a demanding climb that requires a well-maintained braking system for the descent. Despite the intensity of the slope, the road is totally paved and generally kept in excellent condition, making it a favorite for road cyclists and driving enthusiasts looking for a technical challenge in the Dolomites area.
Why is this pass unique?
What sets Passo Castrin apart from other Alpine passes is its configuration. Unlike traditional open-air summits, the highest point of this crossing is located inside a tunnel. Specifically, the maximum elevation is reached at the southern portal of the main tunnel. This architectural feat makes it one of the most interesting and unusual mountain crossings in South Tyrol.
Driving tips for SP-86
Because the road is so steep (19%), it is essential to manage your speed and engine braking carefully. The tunnel is well-lit and modern, but the transition from the bright Alpine sun to the tunnel interior can be sharp. The route offers a direct and scenic connection through the mountains, bypassing older, more winding tracks and providing a fast but thrilling experience for anyone driving through the Bolzano province.