The loop starts and ends in Alhama de Murcia. The RM-502 enters Sierra Espuña and climbs through pine forest to Collado Bermejo, the sierra's classic pass, with views over the Guadalentín valley.
From the col the route descends the other side towards Aledo, a village with a medieval tower on a rocky spur, and continues to Totana on the RM-503 before returning to Alhama de Murcia along the foot of the sierra. It crosses the municipalities of Alhama de Murcia, Totana and Aledo, around the Sierra Espuña Regional Park.
It is about 55 km and almost two hours without stops, with around 250 bends and more than twenty hairpins: the twistiest Murcia route in the gallery. Altitude ranges from about 180 m to 1,200 m. The hairpins are tight and there are many cyclists at weekends.