Cancun is around one hour by air from Miami, and about two from Mexico City, making twin centres with either destination a popular choice for holiday itineraries. The Airport in Cancun is only around 8KM from the sea front area, and taxis are available to shuttle guests between the two places.
You can rent a car in Cancun if you want to explore the rest of the Quintana Roo province, and for day trips to Merida or Chichen Itza it's a great idea.
Boats operate ferry service between Cancun and Isla Mujeres, around 4KM off the coast.