I need a name for a kind of cement block! Was hoping someone here could help.

I visited Vermont last year and they had small cement blocks set into the ground, filled with dirt and grass in the parking lots at the fish hatchery. This was the parking surface for all the lots. I was wondering if anyone knows the correct name for those kind of blocks?

I really thought lot looked wonderful, drained well, and with grass growing out the holes, gave parking area a very soft look. Blocks prevented pot holes, uneven dirt with use, erosion on the mountain tops. Much nicer than asphault or cement surface. Blocks gave a pretty pattern, kind of diamond under grass. They just mowed across the blocks.

I would like to get some of these blocks instead of putting in a sidewalk, just a firm surface to the door, firm edge where driveway fades into lawn. The grassy centers were really attractive too, soak up water, not let it run off. Not a huge focal point like sidewalks in small areas. Just don't know what to ask for at the cement factory! I am sure they are not deep like regular cement blocks, or as big. The idea has really caught my interest, don't want to go to another method. Husband wants a firm surface to walk on that dog can't dig up!!

Thanks for any suggestions.