Beyond public view, scholars unravel mystery of writing in ancient Mexican city

Mexican archeologist Ruben Cabrera, who pioneered excavations at La Ventilla beginning in the 1990s, stands in front of the Patio of the Glyphs where 42 signs and symbols were painted on the floor probably between 300-400 A.D. in the ancient city of Teotihuacan, in San Juan Teotihuacan, northeast of Mexico City, Mexico November 7, 2019. REUTERS/Gustavo Graf

TEOTIHUACAN, Mexico (Reuters) - Among the many mysteries surrounding the ancient Mexican metropolis of Teotihuacan, one has been especially hard to crack: how did its residents use the many signs and symbols found on its murals and ritual sculptures?

The city's towering pyramids reopened to visitors earlier this month as pandemic restrictions eased. But perhaps its most interesting and extensively-excavated neighborhood, featuring a patio floor with rare painted symbols, or glyphs, remains off-limits to tourists.