The first New Year's Eve in Spain comes in mid-December (usually the second Thursday before Christmas). It is the Noche Vieja Universitaria (University New Year), which takes place in Salamanca.
The University New Year is for students of the famous university in Salamanca who will be unable to celebrate the normal New Year with their friends because of family commitments. The students pretend it is not mid-December and go through all the usual New Year's Eve traditions, including the famous grape-eating!
Next up is midday (not midnight) on December 30, in Puerta del Sol in Madrid, for the 'ensayo de las campanadas' (bell-ringing rehearsal) (link in Spanish only). This is actually the first of three rehearsals that the local organizers do to make sure everything is working for the following day, but this is the only one that has been hijacked by the people. Again, this celebration is for those who can't attend the real celebration because of prior commitments - or for those who can't handle the idea of all the crowds that will congregate on the actual day (Puerta del Sol is as busy as Times Square or Leicester Square on New Year's Eve proper).
Later on the same day is the Campanadas Alternativas para Frikis (Alternative Bell-Ringing for Geeks) (link in Spanish only), which takes place at Plaza de Castilla, in front of the Pac-Man tree they have set up there! The Spanish 'friki' (geek or nerd) subculture is quite big. If you feel you fit in to this community, bring yourself along!
Also on December 30, at 8pm, the town of Lepe celebrates New Year's Eve early (and they celebrate it again the following day too!).
Then, of course, comes the real New Year's Eve - December 31. You may be surprised that, for a country famous for its drinking, that most bars will be closed on the stroke of midnight. This is because most people spend the time with their families. However, the city's main square will certainly give you that communal New Year's feeling. They do still party, but it doesn't start until later.
Lastly, there is New Year's Eve in August, which takes place in in the tiny village of Berchules on the first Saturday of the month. Why? Because a power cut in the mid-nineties meant that New Year's Eve had to be canceled, so they rescheduled the big event for August. The re-run was such a success that they've run this second New Year ever since!
Find out what happens on New Year's Eve in Spain. Don't forget your grapes...
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