As everyone knows, Cancun's beaches are some of the world's most beautiful sand and sea destinations. The white sand is cool and never burns your feet. The waters are clean and breathtakingly stunning with every color of the blue spectrum from aqua to sea green to sapphire. But you do have to be careful as sometimes the water can be very rough. Red flags will be posted then and it's wise to pay attention to their warning.
A vacation in Cancun can be relaxing or adventurous, or both. Sunning, swimming, sleeping, and reading are popular pastimes. But for the more adventurous, you can try parasailing over the beaches and inland areas, scuba diving tours can be arranged at your hotel. Fishing, snorkeling, and boating are available as well as day tours to various attractions like Tulum. Shopping tours are also popular. Your hotel desk will arrange anything available for you.
Just remember, the beaches of Cancun are stunning ( and now a little more quiet as Cancun is discouraging Spring breakers as I was told by a limo driver that the damage done to properties and tourism was negative. The push now is toward couples and families).
If you want quiet times but lots of activities and much beauty then look into Cancun for a long week-end or longer. You won't be disappointed. I would definitely go for a 4 or 5 star hotel and the packages are a good value.