One of the bus trips offered when you are in Cancun is a day trip to Xcaret. It is a nice trip because it offers many different activities, including swimming, lying on the beach, horseback riding, and floating in an underground river.
The first thing we did when we got to Xcaret was to get in line to float in the underground caves. I suspect that most of the cave was man made, especially since we came around full circle, but the concept was pretty cool.
We were given life vests and allowed to float with the current or swim along the tunnels of the underground cave. Openings to the outside world were frequent to prevent minor claustrophobia. The ride was very relaxing, but there were a lot of people floating through.
There are Mayan ruins in Xcaret, but we were not able to find anything out about them. You can see them as you walk around the park and there are some additional ones that you can see if you go on the horseback ride.
We were not able to find any type of tour for this feature, and there were no signs posted, but it was still interesting to walk around and find them.
For a lot of extra money, you can go horseback riding. Pete opted for the sun and the beach while I decided to spend even more money at the park (the underground river had a price attached to it, too). The guide gave us information about the wildlife and the vegetation as we rode along the beach out to some small ruins. I found the ride to be really enjoyable.