A fascinating new exhibtion dedicated to the treasures of Teotichuacan, the most important city during Aztec times, has just opened at the Caixa Forum Madrid. It features around 400 artifacts selected from some of Mexico's best museums which were found at the ancient site located on the edge of modern day Mexico City. Visitors to the exhibition will be able to learn how the city's ancient inhabitants lived, their religion and culture, and how they organised their society during the city's 800 year history. Best of all the exhibition is free. You can catch the exhibition at the Caixa Forum (Paseo del Prado 36- look for the wall of plants) until 13th November).