This mercado on the Alameda Leon square, opposite the Cathedral, can be visited also during the day. I did not check if it is open 24/24. I think late evening they close the little shops and they reopen them early morning.
In front of the Cathedral, at the Alameda de Leon there was a market. It was great to walk around, as well during the day as at night. There was a great atmosphere.
What to buy: On this market they were selling all kind of stuff, like T-shirts, local craft, cd’s with local music, food . . . .
Near the Basilica de la Soledad, you also see a lot of stalls who are selling all kind of religious souvenirs. A lot of these souvenirs show the picture of the Virgin de la Soledad.