Professor Tapia is a local historian, author of several papers and books that deal with Ávila Walls. He has a deep knowledge on both history and historical sources. He introduced us to the evolution of the Alcázar gate throughout the history and showed us its main changes as well as the main damage suffered because of wars and time deterioration. It was a good start since professor Tapia had located a lot of graphic information in his previous works that was scattered in different archives and private collections.