Study the messages on the gravestones and try to piece together the history of the region at Montjuic Cemetery. You'll find lots of fascinating stories among the monuments here.
You'll be spoiled for sightseeing choice in Sants-Montjuïc. Montjuic Cemetery is a good place to kick off here, but there are many other fine spots to enjoy. Sagrada Familia, La Rambla, and Plaça de Catalunya are not far from the burial ground and will fill in your day nicely.