I am organising a trip out to take part in a 80km Ultra in the Costa Blanca Mountains - very hilly (5,000metres ascent). There is also a 4km race as well. It takes place at the start of November when there is a full moon, so the night section should be amazing!
Cheap flights to Alicante are available. There are 4 of us heading out so far.
Entries open in July, But brief details are here - https://www.facebook.com/labdet