Chained
Certain things may look a little eerie when you first spot them but believe us, there’s usually a perfectly logical explanation for their existence. When the OP spotted this metal chain running from the top to the bottom of someone’s house, they couldn’t help but wonder what its purpose was.
The internet responded that this was a rain chain that apparently originated in Japan and is used as an alternative to gutters and downspouts. They are mostly decorative and make a pleasant sound while the water flows downwards to a drain, container, or landscaped bed. You learn something new every day!