The first substantial addition to the original Museum building on the Great King Street site was the Hocken Wing, which opened in 1910, housing Dr Thomas Hocken's collection of manuscripts. This collection now forms the basis of the Hocken Collections. Another new wing, named for benefactor Willi Fels was opened in 1930 and today houses the People of the World and Tangata Whenua galleries. A further expansion of the Museum occurred in 1963 when the Centennial Wing was opened to provide additional display space. With all of these separate developments, the Museum had grown to several times its original floor area, resulting in a confusing layout of multiple internally connected wings.