Cross Cuerda Larga is a mountain trail race in Spain’s Sierra de Guadarrama, usually scheduled for mid-October. The main race is 26 km, with roughly 1,500 to 1,600 metres of climbing, making it a short-distance mountain race with significant uphill effort rather than a casual forest run. The 26 km distance is the main draw, and it carries UTMB Index status in the Mountain and Nature categories.
The adult route follows marked mountain trails, with the course published on Wikiloc for runners who want to study it beforehand. There is also a 19 km junior race, which gives the event a wider race-day structure than a single adult start. It draws mountain runners connected to Madrid’s competitive scene, including the Copa de Madrid de Carreras por Montaña, and it also appears in the Copa de Hierro calendar.