Dan Byrne Climbs Alto de Letras
Recognized as the longest climb in the world, the Alto de Letras in Colombia winds its way through the Colombian Andes from an altitude of about 500 m (1,640 ft) near Manizales to an altitude of 3,692 m (12,112 ft) over the course of 82 km (51 miles) at an average gradient of 4% with pitches up to 11%. It’s even tiring to write about.