See this link from two years ago-

https://www.houzz.com.au/magazine/8-breeze-block-features-that-are-a-breath-of-fresh-air-stsetivw-vs~84455706

Are there two of them? You need to take a better picture that shows the whole scene of the pool deck and patio and how they fit in to the big picture. Off hand I will call them room dividers. I'd paint them a bright bold color and put them to work.

Well, they are very 1970s. You can take a sledge hammer to knock them down. You may need a chisel hammer to clean up the concrete surface and/or patch any depressions.