Map is incorrect. Find Ek Balam north of Valladolid, very cool ruins site! Then cool off at Cenote X'Canche (also can't find this on Barclaycard's google maps for some reason...)
Cathedral of San Gervasio
Beautiful cathedral in Valladolid, definitely evokes the colonial feel. Sorry about the sideways picture!
Ret. Convento de San Bernardino
Neat little convent in the city. Great to wander around, but watch out for the geese - they're a little territorial!