I would like to provide an informational post about how to take the ADO public bus from Playa del Carmen to Coba.
You can visit ww.ado.com.mx for the updated bus schedule, times and prices.
The day before I went to Coba, I walked to the Playa del Carmen ADO bus terminal at the corner of Benito Juarez and Quinta Avenida (5th Avenue) and purchased a first class bus ticket to Coba via Tulum. The bus station is on the left side of the road. The staff members at the ticket counter understand English well. The one way fare was 120 pesos. I bought a return bus ticket for another 120 pesos, from Coba back to Playa del Carmen. I would recommend purchasing a return bus ticket, unless you plan on taking a taxi or colectivo back to Playa, as I am unsure where in Coba you can buy return bus tickets. I purchased a ticket for Coba to leave at 9:01 AM and returning at 3:10 PM. The only return bus from Coba to Playa del Carmen is at 3:10 PM. There are typically two buses leaving in the morning (7:00 AM and 9:00 AM). If you only want to go as far as the Tulum ruins, the bus ticket costs 62 pesos each way.
Make sure to bring lots of water, a backpack with snacks, a hat, sunscreen and loose clothing, as the jungle is extremely hot.
When you arrive at the Playa del Carmen bus terminal, listen for your destination to be called and then make your way to the bus. My bus left at 9:01 AM and arrived in Coba at 11:00 AM. You make two stops along the way; one at the entrance road to the Tulum ruins and one at the bus terminal in the town of Tulum. In Coba, the bus drops you off at the corner of a road that runs alongside a lagoon, in the parking lot of a small restaurant. Upon exiting the bus, begin walking down the road along the lagoon, which is on the right of the road. The walk is short and it only takes approximately 7 minutes. The lagoon is crocodile-infested, so you may see one sunning himself on the dock or peeking through the water as you walk. The road will take you to the entrance to the Coba ruins. Purchase an entrance ticket at the ticket window for 64 pesos and enter the ruins site.
Upon entering the ruins site, you have the option to rent a bicycle, pedi-cycle (holds two people with a driver) or a tour guide. A bicycle costs 40 pesos, pedi-cycle costs 190 pesos for two hours and tour guide costs 250 pesos. I rented a bicycle and it was a great way to get around quickly to each cluster of ruins and it also gives you time to explore at your own pace, and the freedom to spend as much time as you wish at each ruin. Don’t forget to climb Nohuch Mul if you are not bothered by heights, the tallest Mayan pyramid in the Yucatan Peninsula at 42 metres! The view of the treetops from the top is breathtaking. The climb down is hard; make sure to hold on to the rope or walk down in a zig zag fashion to avoid falling (the steps are slippery as so many people have climbed on them). It took me 2.5 to 3 hours to get through the ruins.
After you are finished exploring the ruins, you have the option to browse through the handicraft shops in the parking lot of the ruins or try some authentic Mayan Yucatanean cuisine at one of the restaurants in the area while you wait for your return bus. There are a few restaurants in the parking lot of the ruins and also some more in the town of Coba, if you walk back down along the lagoon road (the same way you got to the ruins). There is a restaurant in the parking lot where the bus dropped you off as well. I ate at a little hole in the wall place in the ruins parking lot called El Faison. They had a good selection of food and it was very authentic.
When you are ready, walk back to the restaurant parking lot where the bus dropped you off (along the road beside the lagoon), to wait for the return bus. The ADO bus will stop at this location first and then head down to the entrance of the ruins, right before the gates to the parking lot, and stop at the sign that says ADO on the right hand side of the road. You can wait here also. The journey back to Playa del Carmen takes two hours and you will stop at the Tulum bus terminal as well as the entrance to the ruins to Tulum on the way back. When you get back to Playa del Carmen, just take a taxi or walk back to your accommodations. From Coba, you could also take a taxi or colectivo back to Tulum or Playa del Carmen, but I am unsure of what the cost would be for this.
I highly recommend going to the Coba or Tulum ruins on your own using public transportation, as opposed to booking an over-priced expensive excursion. It is much more worthwhile and provides more freedom for you design your day as you wish, and spend more or less time doing certain things. Taking the ADO bus is very safe and easy. I was a little nervous and worried about the unknown and about what could possibly go wrong prior to actually doing it, but I can now say that I have successfully done this and none of my fears or worries actually materialized. As a cheaper alternative, you could also take a colectivo (shared local minivan) for approximately 40 pesos from Playa del Carmen to Tulum and then take the ADO bus from Tulum to Coba. I have never done this (although I likely will in the near the future), so I can’t comment on the process just yet.
Thanks for reading! Hopefully I have inspired you to visit attractions on your own by using public transportation instead of booking expensive excursions and organized tours with resorts and tour agencies.