Torre Nueva (Torrenueva) Monument · La Línea de la Concepción, Campo de Gibraltar, Cádiz A watchtower built in the time of Philip III, one of the 44 coastal towers that stretched from the Guadiaro river to Portugal to warn, by means of smoke and fire signals, of the presence of Barbary pirates. Photo: Chugairo (CC BY 3.0) What to see and do in La Línea de la Concepción