The Teatro Cervantes is Almería's main cultural venue and its most prominent nineteenth-century building. Built in 1921, it sits on the Paseo de Almería — the main commercial promenade of the city — and its neoclassical facade is a local landmark. The theatre hosts opera, ballet, and drama productions throughout the year and has a programme that would be respectable in a much larger city.
Even if you don't attend a performance, the building is worth a look from outside: it represents the ambitions of a prosperous early-twentieth-century Almería, the agricultural and mining wealth of the province expressed in architecture. Check the programme on arrival; tickets are often remarkably affordable by northern European standards.