Santa Tecla Festival

For ten days each September, Tarragona's old town hands itself over to the festival, and the heart of it is the castells. Crews in coloured shirts build human towers eight or nine storeys high, with a small child scrambling up to top them off while a drummer keeps the crowd hushed. Plaça de la Font is the place to stand for these, though good luck finding an inch of space.

After dark it gets louder. The Seguici Popular winds through the streets with towering giants and snapping wooden beasts, and the fire devils of the correfoc send sparks raining down over anyone daft enough to stand close. There are market stalls, food tastings and fireworks over the cathedral to round things off. Most of it is free, so just turn up and follow the noise.