Pilgrimages may be defined as journeys made to some place with the purpose of venerating it, or in order to ask there for supernatural aid, or to discharge some religious obligation. The idea of a pilgrimage has been traced back by some to the primitive notion of local deities, that is, that the divine beings who controlled the movements of men and nature could exercise that control only over certain definite forces or within set boundaries. Thus the river gods had no power over those who kept away from the river, or could the wind deities exercise any influence over those who lived in deserts or clearings or on the bare mountain-side.