Spain is almost certainly home to more bizarre festivals than any other European country, but this one must surely be the weirdest. Think of the word 'carnival' and you may mentally conjure up images of Venetian masked balls or scantily clad samba dancers in Rio. But the carnival in the neighbouring villages of Ituren and Zubieta, in northern Spain's Basque Country, is a much darker, scarier affair.

Ituren Zubieta carnival
Vincent West/Reuters

Every January, men from one village – wearing sheepskin costumes and bells on their backs – parade to the neighbouring town and perform a ritual dance. According to tradition, the noise made by the bells ward off evil spirits. The bells also wake up the land so it can be ready to give prosperous harvest in spring. Villagers also dress in bizarre and frightening costumes to harass and scare visitors.

The ritual, which is thought to date back thousands of years, is one of many Basque traditions once banned in Spain. The carnival has seen a resurgence in popularity in recent years, though no one now can remember how or why it began.