Come dusk on the 23rd, La Barrosa fills up with families lugging cool boxes, guitars and bundles of firewood. Bonfires are lit along the sand once it's dark, and groups settle around them to eat, drink and sing until the small hours. The big moment is midnight, when people wade into the sea for a dip that's meant to wash off the old year and bring luck for the new one. Some jump the embers, some just paddle and watch.
It's a properly local affair rather than a staged event, so the mood depends on who's near your patch of beach. Bring something to sit on, a few snacks and a jumper for when the breeze picks up after midnight. Walk a little way from the main car parks if you want a quieter fire to join.