Members of the "Colla Vella Xiquets de Valls" team prepare the base of their upcoming human tower during the "XXV Concurs de Castells de Tarragona", Spain. During the event each team builds towers that are between six and ten levels high. Human Towers have become one of the most important cultural traditions in the región of Catalonia for more than 200 years: “Strength, balance, courage and common sense” has become their motto.