We were in Merida three years ago and this time we'd like to stay in Valladolid so we can visit Ek Balam, cenotes and other things in this area. Are there any haciendas to visit nearby? Anything else we should see? We're thinking of 4/5 days in Valladolid then 4/5 days in Isla Holbox. I want to go to Rio Lagartos, and then snorkel with the whale sharks. Does 4/5 days in Valladolid seem like enough, or too much time?