Callosa has been staging this fight between Moors and Christians since 1860, and four days each October the old town hands itself over to it entirely. Around a thousand locals march in their filaes, the costumed companies that split into two camps: Christian pirates, corsairs and the Knights of El Cid on one side, the Moorish Black Guard, Granadinos and Bedouins on the other. You'll hear the dolçaina, a reedy local woodwind, long before you see anyone.
The arrancà sets it all off at noon on the Saturday, bells going and the gunpowder starting. Across the weekend there are entry parades, the tiroteig with its volleys of musket fire, formal ambassador scenes traded between the two sides, and processions that wind through the centre. It's free to watch. Find a spot near the Plaça del Convent, stay for the noise and the smoke, and let the day run on.