Since castells -human towers- were recognised by UNESCO in 2010, the Catalan tradition, which dates back to the 18th century, has been seen all over the world. But there's nowhere better to experience it than in its heartland, the Catalan countryside. Vilafranca is the capital of the Alt Penedès region, famous for its cavas and wines, and every summer some of the best groups, or colles castelleres from around the region are invited to join the Castellers de Vilafranca in a grand display to mark the Festa Major de Sant Fèlix. There's stiff competition to build the highest tower nowadays towers nine or even ten people high are not uncommon. It's a nail-biting wait as the tower rises, with ever smaller castellers climbing up the backs of the lower layers until the youngest child of all reaches the top and raises one arm in the air. The combination of skill, strength and nerve makes for a mesmerising spectacle, and when a tower is raised and dismounted without collapsing, the reaction is euphoric.