This gate was probably once an entrance to the city, but as the city grew, its boundaries no longer coincided with the location of the gate, and the gate came to serve principally as a division between neighborhoods. The gate was probably once a part of the city's defenses, but this function disappeared long before the photograph was taken.
The gate is formidable - it is no light and airy structure. It is no higher than it needs to be to pass wagon loads, nor much wider. It has appreciable length, and so creates a dark area of some extent. It does not especially invite one to pass through.
The gate frames no special view, but one can see that another neighborhood exists on the far side of the gate, possibly one that is a bit wealthier than the neighborhood in the foreground.
Notice how the street funnels into the gate, a typical arrangement.
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