Right in the hotel zone there is a Small Ruins called El rey Ruins. You can easily take a bus there. Only a 5-10 minute bus ride. Right across the street is the Cancun sign for pictures. There is a Mayan Museum as well on the hotel zone. Aqua World is along there as well and have many excursions some of which leave right from there such as the jungle tour where you take small speed boats and snorkel. You can check their website. There is a huge lovely outdoor mall with high end, mid range and souvenir shops as well as places for a meal, drinks etc. It is called La Isla Mall and is also just short bus ride. There are MANY tours to many places from your hotel. One you could take by yourselves is to Isla Mujeres. You can take the ferry which is not far and once there can rent a golf cart to tour the island. There are many things to see there. Just check it here on Trip Advisor and find lots to do there. You can go parasailing and jet ski near the resorts. There are of course fees for those things.