Underground caving tours. Amazing once in a lifetime experience!! Highly recommended for adventuous folks not afraid of being underground. You do have to climb around limestone formations that are not level and in/out of water. Therefore, while not crazy hard, people with knee or back problems should likely sit this one out. RECOMMENDED TO BOOK TOURS THROUGH THE RESORT FOR AUTHENTICITY
Tours to the Ruins can be booked through a variety of tour companies offered at your resort. Make sure to pick a company that has a good guide who will explain the Mayan history of this site! Very intersting. This site can get busy, so if you are Covid concerned you may want to ask about tours first thing in the morning. Most offer a duel trip that will include touring the ruins along with ATVing, ziplining, caving, etc.