Castells is the Catalan tradition of building "human towers."

Forming the base of the tower, called the 'Pinya.'

Young castellers celebrate a completed tower.

A woman watches from a balcony in Barcelona.

The 'Gralla' is a type of Catalan flute and the music helps set the tempo for the building of the castells.

Castellers de Vila de Gracia complete a tower in Barcelona.

Hair needs to be pulled back and tied up so it doesn't get in the way.

Hair needs to be pulled back and tied up so it doesn't get in the way.

The 'Faixa' is the sash that the castellers wear to keep loose shirts and pants tight, as well as aiding the ascent of the other members of the team.

The Xics de Granollers making a castell in front of the church in Girona.