Nicknamed the "bone breaker", Quebrantahuesos will be held on 22 June 2013. It starts in Sabinanigo and crosses into France, taking in four mountain passes (Somport, Marie Blanque, Portalet and Hoz de Jaca) along its 205km route.
For those who don't fancy the full 205km distance, there's a Medio Fondo version of Quebrantahuesos, called Treparriscos, which covers a distance of 90km with only one climb which starts immediately after the Gran Fondo.
The field is limited to 10,000 spaces, which are decided by a ballot as organisers expect more than 17,000 riders to apply to take part. You can put your name down for the ballot on www.quebrantahuesos.com, with the application period closing on 4 January 2013.
If you do make the cut for this event then make sure you head over to our fitness site BikeRadar Training. free online resource for you to record and analyse all aspects of your training, log your training routes,add photos, get yourself tailored training plans, take part in challenges, join training groups, see how you're doing on our leaderboards, set goals and plan your season with a comprehensive events guide.