This Cancun Airport site has important info you need to know about. The Cancun International Airport is a very important airport in Mexico, it is actually the second largest Airport in the country by traffic but the first by International Passengers. On this website you can find important information concerning flights arriving and departing from Cancun. Immigration forms needed. Travel tips. Cancun Airport just opened its new Terminal 4 trying to improve its high standards and also in order to make it able possible to have a higher traffic. Cancun Airport has actually 5 terminals. Terminal 1 for national flights. Terminal 2 for National and International flights. Terminal 3 for International and Terminal 4 for both. The 5th terminal is the FBO for private flights and charters.