Fences or "do you need a mug"?

Need a mug?

The other day I was walking "over the hump" and passed a row of fences. Many of them were decorated with a mugs. In fact, there were hundreds and hundreds of these mugs on the fences.

If someone needed a mug urgently...

I wondered if these "mug fences" were just a Czech specialty or if they were common elsewhere.

Maybe it took years to accumulate so many mugs. Or does OBI used to have a "mugs on the fence" event where you could buy a container of various mugs just for this purpose? Maybe it would be an interesting business project to sell mugs for the fence.

Speaking of fences... A company that sells and repairs pianos has a fence like this.