Archaeologists Find Wartime Weapons in a Yucatán Cenote Beneath a Colonial Convent
A cenote beneath one of Yucatán’s oldest convents has yielded an unexpected cache of weapons and a reminder of how vulnerable the region’s underwater heritage has become. At the Síis Já cenote in Valladolid, Mexico, archaeologists recently recovered 153 Spanish and British muskets and rifles, along with an iron cannon. The objects were likely discarded by the Yucatecan government in the early years of the Caste War of Yucatán, when officials appear to have kept them from falling into Maya rebel hands.
The site lies beneath the 16th-century former convent San Bernardino de Siena, a setting that underscores the layered history preserved in cenotes across the peninsula. Mexico’s National Institute of Anthropology and History, known as INAH, also reported Maya ceramic pieces and 18th-century Chinese porcelain at the site, material that helps trace the region’s long arc from pre-Hispanic ritual use to colonial and postcolonial conflict.
Cenotes are limestone sinkholes linked to the peninsula’s underground aquifer, and they have long served as both water sources and archaeological reservoirs. Arturo Montero, an archaeologist, said cenotes help scholars understand settlements on the continent 13,000 to 15,000 years ago, adding that their conditions can preserve ancient remains with unusual clarity. Roberto Junco, who heads INAH’s underwater archaeology division, said weapons from the Caste War have been found in other cenotes, including those in Homún, but that Síis Já is the only one where an iron cannon has been recovered beneath one of the region’s oldest convents.
The discovery comes with a warning. INAH first explored Síis Já in 2003, then returned in February 2026 after local archaeologist Sergio Grosjean denounced illegal tourist infrastructure at the site, including a wooden bridge. Junco said the water is polluted by sewage and trash, and that catfish once common there have disappeared. The agency also reported evidence of unauthorized diving.
The damage is part of a wider pattern. Infrastructure, tourism, urbanization, agriculture and pork production have all affected cenotes for decades, while activists say the Maya Train project has altered more than 125 of them by driving pillars through their systems. José Urbina, founder of the environmental group Sélvame MX, said the project affected not only the cenotes but the aquifer itself, the region’s only water source.
Junco said diving is not forbidden by law, but touching, removing or documenting remains is prohibited. Plans for Síis Já now include research, conservation and trash removal, while restored objects recovered in 2003 are expected to return to the convent for display.
