Travellers in Spain or those of you that can easily reach one of below Spanish cities have great opportunity to visit classic Caribbean destination. Planning to explore Yucatan peninsula next main tourist season consider this KLM / Air France promotional offer. Note that domestic leg is on their SkyTeam partner AeroMexico. You can now book round trip flights from Madrid or Barcelona to Cancun already for €270! Some of the flights require airport change in Paris on your inbound flight. This is great opportunity to end your trip in Paris. (Remember you can not skip first leg Spain - Paris, rest of your itineerary would be cancelled).
Air France promotional sale is running till 31st of May 2019. Valid for bookings in travel period from September 2019 till March 2020. Blackout period around Christmas holidays. Max stay 3 months. Booking is available directly with the carrier which is also the easiest way to check the cheapest travel dates to Cancun in Mexico.
Booking samples
Spain - Cancun for €294 (Book directly with Air France-KLM)
Barcelona - Cancun for €270
Madrid - Cancun for €272
Booking sample of cheap return flights from Spain to Cancun, Mexico from €270 here. In this case you would fly from Barcelona to this classic Caribbean destination on 28th of January. Return flight from Cancun back to Europe would be on 11th of Feruary 2020.