Landmarks worth the trip on their ownTulum's coastal ruins and Isla Mujeres are the sights most visitors build their first day around, and both reward an unhurried visit rather than a rushed photo stop.
A different pace of daily lifeWandering through Xcaret Park or Playa Delfines gives a better sense of Cancun than any single landmark — it's where the everyday rhythm of the city actually shows.
Chichén Itzá (via day trip)One of the more memorable stops for first-time visitors, and easy to reach from most central hotels.
A natural base for exploring furtherGood regional transport links make Cancun a sensible starting point if you're planning to see more of Mexico while you're there.