The San Boldo Pass is a small mountain pass in the Italian Veneto region between the towns Trichiana. The pass lies at the southern edge of the Alps and connects the Val Belluna with the Val Mareno over a height of 706 m (2,316 ft). The mountain pass is called the SP 635 and only one lane is passable, the traffic is regulated by several sets of lights. There is a speed limit of 30 km/h (19 mph) and a height limit of 3.2 m (10.5 ft), after buses were repeatedly stuck in the tunnel. There are five tunnels blasted into the rock with hairpin turns or loops, and six bridges.