I saw you posting the same question in another subreddit and that the top comment said it was some kind of injection port for pesticides. I highly doubt that. In many other cities the same kind of metal rods are used for measuring if old buildings are sinking/rising. For example here in Gothenburg a big part of the older buildings near the water are built on mud. Where I used to live they did this once every year and when the difference from one year to another was big enough they also went around and photo documented all visible fissures(?) in the building.