African penguins inhabit twenty-seven sites. Most are on inshore islands, of which the best known is Robben Island. There are only three of them on the mainland sites. The largest existing colony is on St Croix island near Port Elizabeth, with about 50000 birds. Dassen Island off Yzerfontein, once home to over a million penguins, now has about 30000, while Dyer Island near Gansbaai has about 20000. The most remarkable of the mainland colonies is Boulders Beach in Simon's Town with over 2500 birds.