A few weeks back, I stumbled upon La Placita de Santurce, a farmer's market known more for its bars than its produce. La Placita is not a place where most tourists go, as it's not located near the beach or any of the tourist areas. Surprisingly, the Puerto Rican Toursim Bureau hasn't really promoted this extremely popular local hangout spot. This is a great place for those who are looking for cheap drinks and interested in mingling with the locals. There are also live salsa bands! During happy hour on Thursday and Friday nights, from what I've been told, La Placita is packed to the gills.
On Sundays, as in most parts of Puerto Rico, nothing much happens in La Placita. We got there at around 1PM and it was already closed. There were a few bars and one restaurant open though. Unfortunately, I don't know what the exact opening hours are for the marketplace. Like most farmers' markets though, it's best to go early. From Mondays through Fridays, they are open during lunchtime. If you'd like to eat some authentic, and affordable, comida criolla (Puerto Rican food), La Placita is your perfect destination.
Check out this great New York Times article on La Placita de Santurce.