The handsome Iglesia y Convento de Santa Teresa de Jesús (Brasil, esq. Compostela, tel. 07/861-1445), two blocks east of Plaza del Cristo [1], was built by the Carmelites in 1705. The church is still in use, although the convent ceased to operate as such in 1929, when the nuns were moved out and the building was converted into a series of homes.
Across the road is the Drogería Sarrá (Brasil, e/ Compostela y Habana, tel. 07/866-7554, daily 9 a.m.–5 p.m., free), a fascinating apothecary—also known as Farmacia La Reunión—with paneled cabinets still stocked with herbs and pharmaceuticals in colorful old bottles and ceramic jars.
Links:
[1] http://www.moon.com/destinations/cuba/havana/sights-habana-vieja/southern-habana-vieja/plaza-del-cristo