Competitors start to form a human tower called "castell" during the biennial competition in Tarragona city, Spain, on Oct. 2, 2016.
A man climbs on top of his teammates as they begin building a human tower.
The competition is the ultimate exhibition of teamwork as large groups of everyday people from the ages of five to 95 work together to build the human structure.
Members of Castellers de Vilafranca start to form a tower.
Members of the Colla Vella dels Xiquets de Valls team perform.
Band members look on as they play drums and gralles.
A competitor is attended to after falling during the competition.
An aerial view of the competitors.
Spectators cheer a team on as they perform.