Top: sky map covering the Virgo cluster. The positions of NGC 4371 and M 87 are highlighted, as well as an area of 16 sq. deg around the centre of the cluster. Bottom: expanded view of the 16 sq. deg box highlighted in the top panel. At the distance of the cluster, NGC 4371 is about 0.4 Mpc away from M 87, which sits near the bottom of the cluster’s potential well. (Adapted with permission from the Deep Sky Hunter Star Atlas; see http://www.deepskywatch.com/ – courtesy of Michael Vlasov.)