Large porphyry cubes are almost cube-shaped paving boundary elements measuring more than 14 cm per side, obtained by mechanical splitting and whose edges are variable. The head of the cube has a natural quarry surface, so it is not excessively rough and allows comfortable walking.

Often used to delimit green areas (gardens, flowerbeds, etc.), this is because it makes it possible to create a delimitation at the same level as the paving, allowing water to flow off the paving and into the green areas.
It also gives a homogeneous appearance, as the differences in shape compared to paving made of cubes are not evident.