Cuesta del Tirón

The Cuesta del Tirón is San Agustín del Guadalix's flagship popular race: it has been held since 1990 and reached its 36th edition in September 2026. It is organised by Enphorma with support from the town hall and draws several hundred runners every year.

The 10K starts and finishes on the athletics track at the municipal sports centre and loops through the town's streets on two different laps. After the first, longer lap, runners come back onto the track at around 6.5 km and then tackle the second lap before the finish. The organisers bill it as exactly 10 km, the layout has stayed the same for seven editions, and the track linked from the race website shows about 90 m of climbing.

Entry is free and includes a T-shirt and food and drink at the finish; timing is by chip and there is a 1 h 20 min cut-off. 2026 saw the debut of a 5 km race, children's races were held on the track and the 10K sold out. That year's charity partner was the Asociación Blue Family, which supports families with autistic children.

First year with a 5 km option (300 places). Both the 10K and the 5K sold out; 354 runners finished the 10K.