Recommended by a friend from Mexico City, these destinations were described as comparable to how Cancun was 80 years ago before tourism.
Three hours from Tulum (Cancun), located in the same state, coastal with Mayan ruins.
https://en.wikipedia.org/wiki/Mahahual
https://www.youtube.com/watch?v=kHckrKzti9g
https://en.wikipedia.org/wiki/Bacalar
https://www.youtube.com/results?search_query=Bacalar