I visited Los Petenes-Ría Celestún during a trip to Yucatán in November 2023. The Reserva de la Biosfera Ría Celestún and the Reserva de la Biósfera Los Petenes cover the north-western part of the Yucatán peninsula, straddling the states of Yucatán and Campeche. The easiest point of access is the village of Celestún. It is possible to stay overnight, but a day trip may be sufficient.

In addition to private cars, there are several ways to get there, with Mérida being the most convenient starting point. Most of the city's tour operators and hotels offer excursions to Celestún. In November, this package cost MXN$1,650 per person and included transport to Celestún, boat trip, guide, and dinner, departing at 8AM and returning at 4:30PM. It is also possible to reach the village by public transport. Buses supposedly depart from Terminal Oriente. Departures were posted on the wall, but no one was at the counter when we tried to get information. Most of these buses would make a detour via Hunucmá, taking over three hours to reach their destination. So we opted for a collectivo. However, we had trouble finding the stop (it's here: 20.961635140864207, -89.61616133941756) and the timetable wasn't really respected. So we waited for the van to fill up, and were at our destination in just over two hours.

Celestún's main attraction is the boat trip through the mangroves and lagoon. It is possible to start from the beach, but the boat captains then must make a detour to enter the lagoon, making the excursion longer and more expensive. You should therefore ask your collectivo driver to drop you off at the Parador Turístico Celestún. The disadvantage of going by public (or private) transport rather than by excursion is that you'll be responsible for making friends at the pier, or you'll have to rent an entire boat. I don't remember exactly, but I think it was around 3,000$MXN. Six people were waiting at the counter when we arrived, so we were able to split the cost and the excursion between eight of us.

I think all the boats do the same route, but the itinerary may vary depending on the season and the location of the birds. We started by seeing the American flamingos for which the reserve is famous. A group of around 200 flamingos were on hand for us. Bring a good zoom lens if you want to take some nice photos. The guide then took us to see some magnificent frigatebirds on an island, a group of roseate spoonbills and an alligator. We then sailed through a narrow channel in the mangrove and stopped for a stroll along a boardwalk in the forest. It's possible to swim here, but another good-sized alligator was watching the water.

After the excursion, we walked to the beach. There are a few more views of the lagoon along the way. More American Flamingos were there. From the beach, we walked north on Route 12, until we reached virtually dry lakes with a pink layer of mud and salt. This road would be the ideal place to observe two species endemic to the region, the Yucatan gnatcatcher and the Yucatan wren. We were only successful with the former. My sighting list for the day also included other interesting species, including black-necked stilt, American avocet, brown pelican, four species of egret, American white ibis, osprey, and olive-throated parakeet.

We ended the day sipping cocktails on the beach. I really enjoyed my visit to Celestún and I think it would be an interesting WHS. I must admit that I'm the target audience, but the boat trip was well organized and a lot of fun. I would recommend that more seasoned birdwatchers spend the night there to take advantage of the cooler morning to make observations. Otherwise, Merida is an ideal base. We also visited Uxmal from there, but other TWHS such as the cenotes and Izamal are also within easy reach.