The "castells" (castles or human towers) come from the "Ball de Valencians" (the Valencians' dance), a dance which was performed as one of the activities of the local town or village festivities in the "Catalunya Nova" area (Southern Catalonia).
The dance consists of foursome dancing which was done to the tune of "gralles" (pipes). This dance ended up by building a small human tower about three or four storeys high. The rivalry between the groups of dancers of the "Ball de Valencians", to see who could build the highest tower got to such lengths that, that which had been the finishing point of the dance got to be so important that it ended up becoming a separate feat from the dancing itself.
The separation was, in fact, gradual so that it is not possible to date exactly when the "dancers" solely wanted to build towers.
The separation came to a head during the last quarter of the eighteenth century. During the first half of the nineteenth century "castellers" (castle builders) were announced in the programmes of the local festivities and called "ball de Valencians"; during the second half of the century the name "Valencians vulgo Xiquets de Valls" (Young popular Valencian dancers) began to spread in the Penedès region.
The gralla pipe music continued to accompany the "Ball de Valencians", even after the separation was completed and also the "castellers".