Large Scale Structure Maps of the galaxy distribution in the nearby universe reveal large coherent structures. The extent of the largest features is limited only by the size of the survey. Voids are present in every survey large enough to contain them.
Many galaxies lie in thin sheet-like structures.
The largest sheet detected so far is the Great Wall. The frequent occurrence of these structures is one of several serious challenges to our current understanding of the origin and evolution of the large-scale distribution of matter in the universe. Although the Leo and Hercules Clusters lie slightly south of this region, the authors make it clear that the same structure extends south of the survey boundaries.