Mexican Army Accused of Illegally Building Over World’s Largest Cave

Tulum, Quintana Roo — The environmental organization Sélvame del Tren has accused the Mexican Army (Sedena) of resuming construction on a purported highway bypass in Tulum that is planned to pass directly over the Sac Actun system, the longest flooded cave in the world. The group alleges the work is proceeding without the required environmental permits, following the project's suspension last year by the Federal Attorney for Environmental Protection (Profepa).

Project Resumes Despite Prior Suspension and Permit Withdrawal

The contested project involves a road that would traverse the Sac Actun system, an underground river network spanning more than 368 kilometers. In September of last year, the Ministry of Infrastructure, Communications and Transportation (SICT) withdrew its request for authorization for the project. The original Environmental Impact Statement had proposed the removal of forest vegetation on 149.64 hectares for a change of land use, the clearing of 39.6 hectares, and the definitive loss of more than 39,000 trees.

Despite this withdrawal and the prior suspension, Sélvame del Tren reports that army personnel have resumed construction. "We traveled the route of what was supposedly a 'bypass' to Tulum, which had been closed by Profepa. This road route passes over the Sac Actun system, the second largest underground river in the world. They have been working illegally," the organization stated on social media.

Allegations of Real Estate Speculation, Not Traffic Relief

The organization's director, Guillermo D'Christy, challenged the official justification for the road, arguing it is not a true bypass but a project aimed at urbanizing the jungle for profit. "It is very clear that this 'road' through the Jacinto Pat ejido is a very lucrative move for a select few through real estate speculation. It is not a bypass because its route does not encircle Tulum," D'Christy posted.

He added, "With this route, this large area of jungle is practically being handed over to destruction, and the underground river systems, which are most densely located in this area, are being jeopardized."

Evidence of Ongoing Work and Environmental Warnings

Speleologist José Urbina, a member of Sélvame del Tren, provided photographs of military machinery working within the vegetation. He described the construction methods, noting, "They’re chipping away at the rock; there are parts where they’ve been filling in the ground. There are a lot of illegal quarrying operations in the area, which used to supply the quarry. So, it’s been easy for them to level the road now."

Urbina issued a stark warning about the project's potential consequences for the region's water supply and ecological heritage. "What these people are doing is condemning Tulum to run out of water. They're destroying the archaeological remains, the paleontological remains, the beauty of the jungle," he said by phone.

He explained the hydrological threat: "These people are putting a line between the water source, which is the Holbox fault, and Tulum. That line, that road they want to build for developments, where they want to put condominiums and other things, is going to drain what little water is left."

Project Details and Official Requirements

The original bypass project was conceived as a 26-kilometer highway intended to connect two points on Federal Highway 307, which runs from Cancún to Chetumal. The route was designed to begin at the Tulum exit in the direction of Carrillo Puerto and end to the north, in Ejido Jacinto Pat. The stated primary objective was to divert heavy and long-distance traffic away from the center of Tulum.

However, the group now alleges the new route deviates significantly from this plan. They accuse the builders of shifting the path about 20 kilometers from Ejido Jacinto Pat towards the Tulum-Cobá highway, a change they argue transforms the project from a bypass into a means to subdivide land for development.

Profepa's position from the closure order in April of last year remains clear. The agency stated then, "It is necessary for those carrying out this work to present their environmental impact authorization and authorization to change the land use and remove vegetation in a forest area." The current construction activity appears to contravene this directive.