Castells a catalan word that can be translated to castles, and is a cultural phenomenon of Catalonia. This tradition, often translated as Human tower, consists of human constructions formed of people climbing on top of each other. These towers have been built in the Tarragona and Penedes area of Catalonia since the XVIII century. From the 1980s, the catalan tradition of building human towers got extended progressively throughout Catalonia and the Balearic Islands, becoming a very powerful symbol of the catalan identity.
From the 16th November 2010, human towers are deemed Intangible Cultural Heritage by the UNESCO.