The history of the kingdom of Yaxchilan, situated on the banks of the Usumacinta River, extends for about 450 years, from 359AD until 808 AD, when it was gradually abandoned and swallowed by the inexorable jungle. It was not until 1892 when Alfred Maudsley became one of the first Europeans to admire the wonderful constructions, stelae and lintels. The Structure 12, with its façade towards the sunrise, is the construction from which the Lintel 48 comes from, which contains an initial set date whose glyphs are represented by heads and four periods of time (baktun, k'atun, winal and k'in) recorded with full body animal figures. The Long Count Calendar is 126.96.36.199.16, the equivalent to February 11, 526 AD, with the Calendar Round 2 Kib '19 Paax.Dra. Federica Sodi MirandaColaboradores: Arqlgo. Hugo Herrera Torres Araceli Ruiz Peláez Mtro. Hugo García Capistran.