This gate stands right alongside the more famous Puerta del Sol and it leads directly to the Cristo de la Luz Mosque. It was originally built in the 10th or 11th century with a Moorish horseshoe-shaped arch and has been subsequently remodelled. Its name comes from the Arabic, bab al-mardún, which means "blocked gateway". It was possibly closed up after the construction of the Puerta del Sol at the end of the 11th century or the beginning of the 12th.
