The Hercules Cluster (Abell 2151) is a cluster of about 200 galaxies some 500 million light-years distant in the constellation Hercules. It is rich in spiral galaxies and shows many interacting galaxies. The cluster is part of the larger Hercules Supercluster, which is itself part of the much larger Great Wall super-structure.
The cluster's brightest member is the giant elliptical galaxy NGC 6041.
from Wikipedia

.This cluster, Abell 2151 in Hercules, is not as rich in galaxies, nor as centrally concentrated, as the Coma cluster. Clusters of this kind may be rich in spiral and irregular galaxies, and in Abell 2151 we see many interacting galaxy pairs and small groupings of galaxies. In both the dynamics of the cluster and its galaxy population, it may be possible to view Hercules as less evolved than Coma. Recent observations show that many Coma-like clusters seen at higher redshifts (and thus as they were several billion years ago) have galaxy populations much like we see today in the Hercules cluster, with numerous spiral and interacting galaxies. Some combination of interactions, mergers, and effects of intracluster gas may be driving this change with time.