When in Bruges and Brussels, next to many entrances I observed an indention in the stone at ground level. Its height/width was about the side of a cat door, and the indention didn't appear to be particularly deep. Usually had a metal strap across it (parallel to the ground). What's its purpose? I am guessing either to scrape your shoes or help pull of boots. But that is pretty mundane, considering these were part of the stone facades.

[Ok, so this post is kind of mundane, but I do enjoy observing these little things.]

It is a boot scraper.

Sorry hit the wrong button!

Nowadays they are often used to chain a bike to.

Thank you!

The purpose of those indentions was indeed to scrape the shoes. In those days the streets weren't asphalted or cobblestoned. It was all sandy and in rainy times (that we have more of enough in Belgium) it got pretty muddy.

Yep, it's a boot scraper. There's one by my front door here in Brussels.