Rio Secreto, the cave river south of Cancun
Rio Secreto is a nature reserve outside Playa del Carmen, and its tour takes you on foot and afloat through a half-flooded cave. It is darker and cooler than an open cenote, and the reserve runs the tour itself. This page covers what happens inside, how to get there from Cancun and who should skip it.
Where Rio Secreto is
The reserve sits beside Highway 307 near Playa del Carmen, at km 283.5. From Cancun's hotel zone it is roughly an hour's drive south, depending on traffic and where you start.
Unlike most trips on this site, the reserve runs the tour itself, with its own guides. You arrive, change into its gear and go underground with a small group.
Inside the cave
The route is a mix of walking and swimming through a semi-flooded cave. Stalactites hang from the roof and stalagmites rise from the floor, the formations described on the Wikipedia page on stalactites.
You wear a wetsuit and a life vest with water shoes, plus a hard hat with a headlamp. A bilingual guide leads the group and explains what you are looking at as you go.
The pace is slow and steady. Most of the light comes from your headlamps, with daylight reaching in only through a few openings in the rock.
What the fare includes
The Rio Secreto tour at ~$89 holds 4.7 from 500+ reviews on GetYourGuide. The price covers all the gear and the guide, and a towel and a locker come with it too.
After the cave there are showers and hammocks, then a light lunch of local food. Tips are not included, and photos are sold by the reserve; your own camera usually stays in the locker, so check the listing.
A cave instead of a pool
Rio Secreto's own guided walk and swim through the underground river, with a wetsuit, a headlamp and lunch afterwards. Choose transport when you book if you need it.
Getting there from Cancun
The GetYourGuide listing runs 4–6.5 hours, and transport from Cancun is an option you pick at booking. Without it you make your own way to the reserve, which is simple with a rental car and harder by bus.
The Viator ticket, rated 4.5 from 100+ reviews, starts at the reserve on Highway 307 and lasts about 3 hours. It suits travelers already staying in Playa del Carmen or driving down the coast.
The price was the same on both sites when we looked. Our guide to cenote tour prices shows how it compares with the other four trips once fees are counted.
How it differs from an open cenote
An open cenote is a sunlit pool where you swim at your own speed. Rio Secreto is a guided group moving through a dark passage, with cooler air and water, and no sky above you.
If you want sun shafts and jumps, the jungle cenotes on the Ruta de los Cenotes fit better. Our page on cave, semi-open and open cenotes explains the difference in more detail.
Who should skip it
The listing says the tour is not for pregnant women or for people with claustrophobia. Passages are narrow in places, and the only light around you may be your own headlamp.
Children who dislike the dark may struggle, so check the age rules on the listing before booking for a family. Our page on cenotes with kids compares the five trips for younger travelers.
If cold water worries you, the wetsuit helps a lot. Our page on depth, cold and safety in cenotes covers the water temperature and the life vests.
Rules underground
Caves like this one usually ask you not to touch the formations, since oils from skin can stop them growing. Follow the guide's line through the water, and keep your headlamp pointed ahead rather than into other faces.
Stay with the group the whole way. The light is low, and the guide sets the pace for everyone, including the slowest swimmer.
The life vest stays on in the water, so you float without effort even where you cannot touch the bottom. Strong swimmers may find the pace gentle; nervous ones usually find it reassuring.
Rio Secreto against the other trips
Rio Secreto costs more than the three-cenote half day, but it includes lunch and a towel, and it offers something none of the others do. It is the only trip here that spends its time inside a cave rather than in sunlit pools.
The longer days pair a cenote with ruins. The Chichén Itzá day adds 12 hours of travel and sightseeing, while the Tulum and turtles day adds a snorkel in Akumal bay. For a single focused swim, Rio Secreto keeps the day shorter.
Some travelers combine two trips on separate days, an open cenote one morning and the cave another. That gives you both kinds of water without squeezing them into one long outing.
Making the most of the visit
Like most cenotes, the cave expects you to wash off sunscreen and insect repellent first. Arrive with clean skin and leave lotions in the locker.
Wear swimwear under your clothes so changing is quick, and bring a dry set for the ride back. Our packing list for a cenote day has the rest.
Since the cave is lit by headlamps and sheltered from rain, Rio Secreto works on cloudy or wet days when an open cenote looks dull. Our guide to the best time for a cenote swim covers the weather through the year.