Get picked up at your Cancun or Playa Mujeres hotel, or choose to meet directly at the Rio Secreto Nature Preserve.
At the preserve, listen to your guide give a safety briefing. Don your equipment, including a hard hat, lamp, wet suit, life vest, and water shoes.
Head underground with your guide and make your way past the floor and ceiling crystal formations. Walk along the designated path or swim and wade through the underground river. Move along with the river, and view the colors and mineral forms that lie all around it.
Exit the cave and opt for a shower. Enjoy a buffet lunch and spend some time exploring the nature preserve or relaxing. Finish the tour with a ride back to your hotel or Plaza Kukulcan.