We always suggest starting on the beach—it’s a vacation, after all. Spend the middle days exploring, first down the coast to Puerto Morelos  and Playa del Carmen , and then inland to Maya ruins like Chichén Itzá  and Ek’ Balam ; definitely consider renting a car for these days.
Returning to the coast, you can catch a ferry to Isla Cozumel or Isla Mujeres  for some snorkeling and island time. Then it’s back to Cancún for one last day on the beach (or enjoying underwater art), and you’re done!
Arrive in Cancún . If you’re staying in the Zona Hotelera, head straight to the beach after you check in—the beautiful beach will be a welcome sight after hours on a plane. If you’re staying downtown, you can either hop on a bus to the beach or stroll around Parque Las Palapas . In the evening, head to dinner at one of Cancún’s fabulous open-air eateries.
Spend the morning on the beach or by the pool. In the Zona Hotelera, you’re just steps away from either. Those staying downtown can take a bus to one of the public beach areas—Playa Delfines  has a bus stop right in front and El Rey , a Maya ruin, across the boulevard when you need a change of scenery. After a day in the sun, unwind some more at one of the Zona Hotelera’s outdoor lounge bars , or head downtown to catch some jazz.
Spend a day exploring the Riviera Maya . A rental car makes life easier, but it’s certainly doable by bus or taxi. Playa del Carmen  and Akumal  make for interesting exploring and could easily take up your entire day; if you like snorkeling, consider going to Puerto Morelos , Laguna Yal-Ku , or Cenote Manatí .
Leave bright and early to get to the Maya ruins of Chichén Itzá  before the crowds do. Spend the morning there, followed by lunch in the colonial city of Valladolid . From there, go swimming in nearby cenotes, or visit Ek’ Balam , a much smaller ruin. Both Valladolid and Ek’ Balam have good lodging options, if you want to turn this into an overnight trip.
Spend this day on either Isla Mujeres  or Isla Cozumel , both easy to reach by ferry. Divers can plan on enjoying a tank or two, especially at Cozumel. If you prefer snorkeling, trips can be booked at dive shops or on the ferry pier of either island. Or just chill out on the beach—Playa Norte in Isla Mujeres  is a sure bet, and the windswept eastern side of Cozumel  is a great option for beachcombing. Either way, definitely think about renting a car or golf cart, which allow you time and flexibility to explore either beyond their central areas.
Back in Cancún, this is your last full day. If you’re up for it, book a snorkeling or diving tour of the Museo Subacuático de Arte  (Subaquatic Museum of Art), a remarkable collection of underwater statues located between Cancún and Isla Mujeres. Otherwise, sit back, relax, and enjoy the pool and beach—it’s been a busy week!