What is the purpose of "Holy Hill" for the Shakers in the book, The Gift of Sarah Barker?

The Holy Hill exists on Shaker land for the observance of Mountain Feast days. Shakers observe rituals that include periods of prayerful silence, processions in perfect rows to meals, and meetings and ceremonies that include the frenzied dancing or "shaking" that gave the group its popular name. Shakers sing hymns of praise for love and freedom, while their lives are rigidly ordered to discourage personal expression.