It looks like it's made out of common soviet time concrete prefab templated decorative blocks. They used it for a lot of things, including decorative walls; you can sometimes spot remains in some courtyards and locations. Around this neighbourhood, there is a bunch of similar architecture with retaining walls. This was probably something like that. I passed here briefly and I don't really remember any more. I will probably pass through here at some point again and may be check it out.