Examples of two proto-clusters at redshifts 1.666 and 2.8335 with 148 and 22 members, respectively. The proto-cluster members are shown as red-filled circles, while non-members inside the proto-cluster radius are shown as blue circles. Other non-members outside the proto-cluster radius in three dimensions are shown as small black dots, and members of other proto-clusters are shown as full green circles. The large black circle indicates the estimated proto-cluster radius, whose size is indicated in the top left corner of the plot.