This video will make you hold your breath. 'Castellers' in Spain are people who create incredibly tall human towers in a sea of... more humans.
A long running tradition throughout Catalonia, Spain, these brave souls struggle and shake as smaller and smaller folk climb to the top of each 'tower.' The annual competitions held in thw town of Tarragona showcase ever-developing techniques since the tower building began at the end of the 18th century.
The crowd of people watching as each tower grows taller doubles up as support for those 'castellers' climbing to the top - arms entwined to catch anyone that may fall. The 'colles' (or groups of 'castellers') create the towers via three main parts: the 'pinya' or base, then the 'tronc' (or trunk), and lastly the 'pom de dait,' which includes also the 'anxaneta' at the very top, made up of small children. They wear helmets, don't worry.
Check out this video, made by photographer Mark Randolph that delves deeper into the excitement, anticipation, and breathtaking heights they reach.