Extend your holidays. Book from 21 days on and Dunas, Hotels, Spain offer you extra days for free, special room rates starting from 60,90€.- From 21 to 27 days = 3 days free- From 28 to 34 days = 4 days free- From 35 to 41 days = 5 days free- From 42 to 48 days = 6 days free