Abstract: A paving block and a paving block assembly include a prism-shaped paving block body having a top surface, a bottom surface disposed opposite the top surface and a first pair of opposing side walls and a second pair of opposing side walls. The first and second pair of opposing side walls are disposed between the top and bottom surfaces with respective ones of the first pair of opposing side walls and the second pair of opposing side walls connected perpendicularly to each other. The top surface has a plurality of longitudinal grooves which are formed therein and extend parallel to each other. Each one of the plurality of grooves has a width substantially equal to each other. The paving block body has at least one projection connected to one of the side walls and positioned between the top and bottom surfaces. The at least one projection projects from the one side wall a distance equal to or substantially equal to the width of the grooves.