If you keep walking 1st Avenue direction South, you will eventually get to 1st Street, the last of the numbered streets in Antigua. Keep walking south and you will get to Chipilapa Street, turn left and then right, and you will get to San Francisco Church.
The church of San Francisco lies behind the gates in the picture. The building was half destroyed during the big earthquake, but was partially reconstructed. Today the interior of the church is in perfect condition, and on Sundays hosts a mass.