In October 2019, archaeologists just outside Mexico City uncovered a 27.5-foot-long, 17th-century tunnel adorned with Aztec rock etchings. Now, reports the Associated Press (AP), researchers have announced plans to rebury the landmark discovery, as Mexico’s National Institute of Anthropology and History (INAH) no longer has the resources needed to convert the site into a tourist attraction or otherwise preserve it.
“It must be considered that the worldwide Covid-19 health emergency forced all levels of government to place priority on assigning money to health care for the population,” says INAH in a statement, as translated by the AP. “For that reason, the archaeological project had to be postponed.”
According to ARTnews’ Alex Greenberger, archaeologists unearthed the tunnel outside the former Aztec capital of Tenochtitlán. It was part of the Albarradón de Ecatepec, an expansive infrastructure system designed to mitigate flooding. Spanish viceroy Juan de Mendoza commissioned the project in the early 1600s to stop water that entered the city from the nearby Xaltocan and Zumpango lakes, per a 2019 INAH statement.
To protect the historic structure until work can resume, INAH will cover the tunnel’s artworks, which appear on a sluice gate used by the city’s early colonial government, with soil, reports Isaac Schultz for Gizmodo. As Live Science’s Yasemin Saplakoglu wrote in 2019, “The tunnel likely served as part of a floodgate for a dike—through which water entered on one side and exited on the other—that was created to control the constant flooding that ravaged the lands.”
Though its artwork features pre-Hispanic designs, the tunnel’s architecture appears to draw on European influences. Per Live Science, around 3,000 Indigenous laborers constructed the dike under the direction of Spanish friars Jeronimo de Aguilar and Juan de Torquemada.
The flood control network protected the city for some 20 years. Then, in 1629, a massive flood inundated the tunnels, overwhelming the system before subsiding five years later. During this period, Spanish colonizers covered the decorated floodgate with stone and ash; according to Live Science, authorities later commissioned two other gates to replace the old one.
“One objective of our project was to know the construction system of the road, which has allowed us to prove that it does not have pre-Hispanic methods, but rather semicircular arches and andesite voussoirs, lime and sand mortars, and a floor on the upper part, with stone and ashlar master lines,” said the researchers in the 2019 statement, per a translation by Peter Dockrill of Science Alert. “Everything is Roman and Spanish influence.”
Found at the east end of the tunnel, the 11 rock carvings and stucco reliefs depict the head of a bird of prey, a flint, a war shield and raindrops. The last of these designs may reference Tlaloc, the Aztec god of rain. As Live Science noted, the team also unearthed four iron nails and two 21-foot-long wooden planks.
Experts are unsure who created the artworks but suggest they may have been made by craftspeople who lived in the nearby pre-Hispanic towns of Ecatepec and Chiconautla. Artisans sculpted the images and then painted them with limestone.
Authorities initially planned to replace the carvings and stucco reliefs with replicas and move the originals to a local community center, as Mexico News Daily reported in 2019. Though INAH officials hoped to open the tunnel to the public, these plans have been put on hold indefinitely as the country struggles to contain the Covid-19 pandemic.
Mexico’s response to the ongoing public health emergency has been widely criticized, with experts calling attention to the country’s “unwillingness to spend money, do more testing, change course or react to new scientific evidence,” as Eduardo Verdugo wrote for the AP earlier this year.
In May, an analysis published by the Institute for Health Metrics and Evaluation at the University of Washington School of Medicine placed Mexico’s estimated Covid-19 death toll at 617,127—183 percent higher than the official figure of 218,007. Per Nicole Acevedo of NBC News, this disparity stems from the country’s low testing rate and the fact that many victims died at home without undergoing testing.