Members of the "Colla Jove Xiquets de Tarragona" during the construction of a human tower during the 25th Tarragona Castells Competition, in Tarragona, Spain, Oct. 5, 2014.
The "Castellers," who build the human towers with precise techniques, compete in groups, known as "colles" at local festivals. Their goals is to build the highest and most complex human tower.
The Catalan tradition is believed to have originated from human towers built at the end of the 18th century by dance groups.
