There's at least one National Union of Cuban Writers and Artists per province in Cuba, but if you visit only one, make it here. Situated in the lovingly restored Casa de las Moyúas (1845) on car-free Calle Manduley, this friendly establishment offers literary evenings with famous authors, music nights, patio theater (including Lorca) and cultural reviews.
There's an intermittent bar on a gorgeous central patio and an on-site art gallery/studio called La Cochera.