Alto de Letras is a high mountain pass at an elevation of 3.692m (12,112ft) above the sea level, located on the boundary of Tolima and Caldas departments, in central Colombia. It’s one of the hardest and most epic climbs you can ride on two wheels.
Located in the Andean region, in the center-west of the country, the road to the summit, colloquially also called “Letras”, is called Ruta Nacional 50 and links Manizales and San Sebastián de Mariquita cities. This ride is spectacularly unique. As you go up, you see how the landscape and climate change, also crops and animals. It is one of the greatest cycling experiences in South America, starting at a sub-tropical 468 meters, in the town of San Sebastián de Mariquita, and topping out at an arctic 3.692 meters.
The road to the summit is paved and considered to be among the most challenging climbs in the world. The drive offers beautiful and changing landscapes and the environment becomes more dramatic and surprising as you go up. Remember this is a mountainous area, climbing up a high mountain, with a notorius absence of oxygen. The road is pretty busy: expect heavy traffic.
It’s said to be the longest road climb in the world. Starting from San Sebastián de Mariquita, the ascent is 78.9 km long. Over this distance, the elevation gain is 3.220 meters. The average percentage is 4 %. The climb maxes out at around 11% or 12% in a few places. Colombia’s famous cyclists have pedaled the Alto de Letras on the Vuelta a Colombia (Tour Colombia).