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. Picture taken November 7, 2019. REUTERS/Gustavo Graf