There's much dispute in Europe about where exactly Columbus is from--fortunately it's much easier to confirm where exactly he went. One of those places was Sant Jeroni de la Murtra Monastery, where he met up with the Catholic Monarchs after his first voyage to America. A short drive (depending on traffic), or a somewhat more complicated journey in public transportation from Barcelona's city center, the monastery is located in Serralada de Marina Park.
For a few euros, you can explore the cloisters, the courtyard, and a small chapel. As you stroll the monastery's elegant arched walkways, try to spot busts thought to be portraits of Queen Isabel, King Ferdinand, and Columbus himself.