Sky plot of the Voronoi Monte-Carlo overdensity map encompassing a large fraction of the VUDS coverage in the COSMOS field. The redshift bound over which the Voronoi tessellation is calculated is set to 4.53 < z < 4.60. Both spectroscopic and photometric redshifts are treated statistically following the prescription in Sect. 3.3 and used generate 500 realizations of the overdensity map in the field. These 500 maps are then median combined and smoothed with a Gaussian of FWHM = 4.5 pixel to create the plotted map. A color bar indicates the magnitude of the overdensity in each 75 × 75 kpc² pixel. The dashed line indicates the extent of our z_spec member cut (R_proj = 2 Mpc). Small black dots denote galaxies with secure spectroscopic redshifts at z > 3 from VUDS and filled circumscribed blue diamonds denote those within the range of PCl J1001+0220. The PCl J1001+0220 proto-cluster exhibits coherent overdensity (log (1 + δ_gal) > 0.5) over an area of 7.58 Mpc².