According to the owner of Juárez Hermanos forged metal shop, this big door (portón in Spanish) is probably the only metal door in Antigua (outside door that is). This is so because only wooden doors are allowed.
Another interesting fact is that the door knocker is very high; you can see it on the upper side of the door painted gold. He said, in colonial times, these door knocker were set high on the doors so you can knock them without getting off your horse. Come back in the next following days to see more things from this forged metal shop.
You can see a previous door knocker posted on this blog by knocking here.