Alto de São Macário is a mountain pass at an elevation of 1.052m (3,451ft) above the sea level, located in the district of Viseu, in the Central Inland of Portugal.
Located in the Maciço da Gralheira mountain range, the road to the summit is called CM1123. It's asphalted, but narrow, unprotected by guardrails and very steep. The last part of the climb is concrete. At the summit there’s a monastery called Santuario de São Macário and several communication towers.
There are 2 routes to reach the pass. Starting from Sul (Viseu), the ascent is 9.05 km long. Over this distance, the elevation gain is 820 meters. The average percentage is 9 %. And starting from Aldeia de Sul, the ascent is 9.2 km long. Over this distance, the elevation gain is 840 meters. The average percentage is 9.1 %.