They are the largest known gravitationally bound structures in the universe and were believed to be the largest known structures in the universe until the 1980s, when superclusters were discovered.
Gugusan galaksi merupakan struktur ikatan gravitasi terbesar di alam semesta dan diyakini sebagai struktur terbesar yang dikenal di alam semesta sampai tahun 1980-an, ketika gugusan super (supercluster) ditemukan.