A biosphere reserve with blue waterways and wildlife. You can take a boat tour here, Cooper and I plan to do this on our honeymoon :)
Cenotes are natural swimming holes, some underground caves and some above ground. Cooper and I visited this Cenote on our last trip and enjoyed it, but there are many cenotes in the area you can check out. Some cenotes are even incorporated into bars right on the beach road.
Mayan ruins overlooking the ocean. You can tour the ruins but expect crowds for this popular site. I have read that early mornings are not as crowded.
You can check out the public beach for more of a local vibe or go to a “beach club” usually connected with a hotel and use their beach chairs/daybeds for a food/drink minimum. If you stay at a hotel on the beach access to their beach would be included.
The town is full of local souvenirs, street tacos, delicious restaurants and coffee shops.
A 2 hour drive from Tulum, you can make a day trip to one of the seven wonders of the world. There are also cenotes you can stop at along the way.