Russian Sinkhole propaganda ?

I got curious and looked up a bit on the town of Solikamsk. It appears to be a well-know salt mining area, with salt mining operations going back as far as 1430.
I also found this article mentioning the temporary cessation of operations at a potash mine. The article, although brief, mentions the possibility of backfilling the mine in question being dangerous.

I get the feeling that mining in this area, with such a long history of mining operations, gets pretty hazardous. Sinkholes may simply be inevitable after this long.

I have a question and I really have no clue as to the answer. I don't know if I should be suspicious or if nature is just weird this way..... However.....

Sinkholes I'd see from the truck and interstate highways were never perfectly round and sheer round walls, as if someone deliberately dug it for a giant well. They aren't wild shapes either, as I recall, but never did I see the perfect symmetry that some of these BIG ones have.

Another in South America appeared in the middle of a residential area, similar to this one, and like it? It also had the same round, sheer and smooth walls.

Here is another question..and one I haven't seen addressed. What, if we even know, do these areas look like underground BEFORE the final 'sink' exposes the issue to everyone top-side? Are there even any simulations to guesstimate what formation of these look like before they break the surface ..or suck it down?

It looks too artificial, and this is by far NOT the first one to cause me to think that way...just, perhaps, one of the largest.

Sorry, the first thing I thought of when I saw the holes.

I know, I should be ashamed of myself. . . .
 

Damn, Now that's One Hell of a Night Crawler.... wow Great pictures and explanation of the holes.

@solarius,

After taking a closer look through photoshop if I was a betting man I would say it was shopped. Under magnification the pixel accuracy appears to be incorrect around the opening. The photo from far away under magnification also appears to be slightly in the wrong plane in comparison to the ground, and curiously there is a road on the left of the photo along the tree line that shows two telephone poles behind houses that are not there in the other photo, even under different lighting conditions. I changed the lighting just encase they blended in with the trees but they didn't. It would be much better if we had good color photos, but there is a reason for that if they aren't available.