Summary:
Castells de Barcelona, a group of acrobats, have been performing the stunt at the La Mercè festival.

Full article:
It is the unusual Catalan celebration that sees locals form precarious human pyramids. And this year's La Mercè 2014 festival, in Barcelona, Spain, was no different, with 36 people clamering on top of each other to form the amazing tower. The group of acrobats performed the stunt which is known locally as 4 de 9 amb folre (9 levels of 4 people) in the Sant Jaume Square area of Barcelona. All of the acrobats wear matching outfits and they show composure and discipline to complete the challenging routine. The performers all take up individual responsibilities with a multitude of the acrobats supporting their colleagues on the bottom while others climb up to the top of the group. It takes the dozens of acrobats one minute and 40 seconds to assemble the impressive human pyramid and there is a rapturous round of applause from the audience when they complete the task. It takes the group one minute and eight seconds to dismount the human pyramid and as they do the participants cheer and congratulate each other on a successful performance. Start: The Castellers de Barcelona acrobats prepare to assemble to perform their stunt . Nine levels: The stunt which is known locally as 4 de 9 amb folre (nine levels of four people) Support: Some of the acrobats support their colleagues while others climb up to the top . Finale: The Castellers de Barcelona group prepare to finish off their impressive performance .