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 the central part of Colombia. It’s one of the hardest and most epic climbs you can ride on two wheels.
Set high in the Andean region, the road to the summit, colloquially known as “Letras”, is 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.
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. The road is pretty busy: it is recommended to start early to avoid heavy traffic.
Starting at San Sebastián de Mariquita, the ascent is 78.9 km (49.02 miles) long. Over this distance, the elevation gain is 3.220 meters. The average percentage is 4 %.
At this length it is definitely one of the most challenging climbs ever. It’s said to be the longest road climb in the world. The climb maxes out at around 11% or 12% in a few places. It is one of Colombia's most well-known routes for amateur and professional cyclists alike and the most famous cyclists of the country have pedaled the Alto de Letras on the Vuelta a Colombia (Tour Colombia). 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.