Back in 1958 long before the first cinder block was laid in Cancun, Akumal began as a tourist destination. Back when you could get a hot-dog for a nickle in Times Square and the Giants played in the Polo Grounds and the Dodgers in Ebitts Field, Akumal began as a tourist destination.
With the demise of Cuba as an American tropical play-ground Akumal began receiving tourists.

Nearby is Xel-Ha. Today Mexico 307 from Cancun to Akumal and on to Tulum is a safe quality highway.

Side trips to consider are visits to Coba a Mayan city from the VII century. The pyramid there Nohoch Mul is higher than that of Chichen Itza.

Another side-trip could be Tulum another archeological zone from the postclasical period.
There are 60 buildings to see in Tulum although some of them are quite boring. But the trinket shops are neat.

Sian Ky'an is an ecological reserve of 527,000 hectares. I don't know how much that is in acres but it's big.
There are flamingos; tucans; deer; unfortunately some mosquitos; and abusive prices for the one group that has the monopoly to do so to tour you in there.