Islas Marías: From Mexican Alcatraz to Eco-Tourism Paradise 

Located roughly 80 km, or 60 miles, off the coast of the state of Nayarit, the Islas Marías archipelago has long been a name spoken more with caution than curiosity. For over a century, from 1905 to 2019, its largest island operated as a notorious penal colony often referred to as  the “Mexican Alcatraz.” 

Its history of housing inmates in a remote, high-security environment created an aura of mystery and isolation. However, in a remarkable turnaround, the archipelago has been reborn as the “Muros de Agua José Revueltas” Biosphere Reserve, named for the writer imprisoned there. It is now opening its doors to a new kind of visitor: the eco-tourist.

The islands’ past is inextricably linked to their present. The very isolation that made it an ideal prison also acted as a powerful conservation tool, protecting the ecosystems from mass development. Visitors today can see remnants of this history, including the old administrative buildings and the pueblo where some inmates lived with their families under a unique model of relative freedom. This stark contrast between the man-made structures of confinement and the wild, untamed nature that surrounds them is a central part of the islands’ unique narrative.

Tourism and Ecology

Ecologically, the Islas Marías are an ecological treasure trove. The separation from the mainland has allowed several species to evolve in unique ways. One of the most iconic is the Islas Marías raccoon, a distinct subspecies found nowhere else on Earth. The islands are also a critical sanctuary for birdlife, hosting endemic species like the María Madre chachalaca and the critically endangered María Madre parrotlet (no, that is not a typo). The surrounding waters, part of a vast marine protected area, are rich with coral reefs, dolphins, manta rays, and, during the winter months, migrating humpback whales.

Current attractions for the intrepid traveler are a blend of nature, history, and science. Guided tours lead visitors through the historical prison site, offering a sobering look into its operational days. Hiking trails wind through dry tropical forests and along dramatic cliffs, providing opportunities for birdwatching and wildlife spotting. The crystal-clear Pacific waters are ideal for kayaking, snorkeling, and diving, revealing a vibrant underwater world. A key component of the new vision is the Muros de Agua José Revueltas Environmental and Cultural Education Center, which details the islands’ dual legacy of human history and natural history.

The “other” Islands

Though La Isla María Madre is the largest and has the most infrastructure, the archipelago is made up of four islands in total. Isla María Magdalena, the second largest island. Unlike its neighbor, Magdalena was never home to the penitentiary, and as a result, it feels far wilder and more untouched. Its landscape is characterized by rugged hills and a coastline that alternates between rocky cliffs and sheltered coves with sandy beaches. This isolation makes it a crucial sanctuary for wildlife, including large seabird colonies and endemic reptiles. The waters around its shores are particularly known for their clarity and rich marine life, making it a prime spot for snorkeling and diving expeditions launched from María Madre.

Further north is Isla María Cleofas, the smallest and most challenging to access of the three main islands. Cleofas is essentially a rugged, uninhabited outcrop, a fortress of rock and dense vegetation rising from the sea. It lacks the beaches of its siblings and is primarily a haven for scientists and the most adventurous explorers. Its primary significance is as a research station. For tourists, it is typically only seen from a distance, a stark reminder of the raw, untamed nature that defines much of the archipelago.

Finally, there is the remote Isla San Juanito, a tiny island located off the northwestern tip of María Madre. It is geographically notable for its distinctive volcanic rock formations and is another key site for breeding seabirds. Like Cleofas, it is uninhabited and not a standard tourist stop.

Getting to Las Islas Marías

Getting to the Islas Marías is an adventure in itself and is strictly regulated to align with its new status as a protected biosphere reserve. There are no regularly scheduled commercial flights to the islands.

Access is controlled and primarily facilitated through organized tours. The main point of departure is the Pacific coast port of San Blas in Nayarit. From here, authorized tour operators provide the only legal access for tourists via boat. The journey by sea is significant, taking approximately four to six hours each way on vessels that range from faster pangas to larger, more stable boats. It is essential to be prepared for this open-ocean transit, as conditions can vary.

Visitors must book through a licensed tour company that has permission to operate within the Muros de Agua José Revueltas Biosphere Reserve. These tours are typically all-inclusive, covering transportation, meals, guided activities, and lodging, and they are designed to be low-impact and educational. The infrastructure on Isla María Madre is basic and focused on sustainability, not luxury resorts. However, there are signs (quite literally, in the Mexico City airport) that the island chain is likely to be receiving a few upgrades, though these are likely to be modest and centered on the largest of the four islands, Isla María Madre.