Filmmaker: Mike Randolph

Across Catalonia, a Spanish region on the coast of the Mediterranean, there is a tradition of building human towers that are seven, eight, nine or even ten storeys high. Every other year in the city of Tarragona, the "castellers" gather and attempt to out-do each other in terms of height, complexity and form.

In a traditional castell, the short, stocky men are at the bottom, followed by those men with better balance, followed by women, and then children on the top. For safety, the children regularly wear protective headgear, but injuries are not uncommon. There are plenty of ambulances on hand, and most injuries are limited to a sprained ankle or a nosebleed.

Each team tends to wear matching shirts, and each participant also wears a tight sash that supports the lower back and is used as a handhold or foothold for those climbing the tower. The most difficult part is not the construction, but taking the tower down again afterwards. As a result, only towers that are successfully completed and then dismantled without collapse are judged "descarregat" - the best rating on offer.