Distribution of groups in the sky plane in a slice of thickness of 20 h⁻¹ Mpc at a distance interval 210 − 230 h⁻¹ Mpc which partly covers the Corona Borealis supercluster at RA = 230°and Dec = +27°, and the Bootes supercluster at RA = 207°and Dec = +28°, and the low-density region between and around them. The sizes of the circles are proportional to the richness of the groups. We only plot the location of the brightest galaxy of any given group. Colours code the limits of global density D8 in the environment of galaxies.