In reply to Jus:
well there is climbing throughout the island more or less..
near heraklion is voulismeno aloni, and skotino cave
http://www.vrahomania.gr/voulismeno-aloni/
id say my favourite though is agiofarago in the south, (villages like sivas/matala are closeby)
http://www.climbincrete.com/en/Climbing/Agiofarago
south of rethymno is plakias but can be too hot now i guess,
http://www.vrahomania.gr/plakias/
patsos in rethymno is nice too and in chania therisso and the beautiful cave of tersanas
there are some guides but you can try also the "allclimb" app, it has crete for free, not entirely accurate but its ok