The material creations of human beings, such as buildings, objects and works of art, are visible expressions of cultural heritage. Apart from these concrete manifestations, cultural traditions and practices passed from one generation to the next form a collective cultural heritage that guides people's behaviour. This heritage manifests itself for example in customs, models of behaviour, oral and written tradition, rituals and rites. Through our actions, we participate in the perpetuation and also renewal of cultural heritage in various ways. Our culture changes constancly, and in order to construct our cultural identity in the midst of this change we need knowledge of our cultural heritage. Thus cultural heritage helps us to situate ourselves in time and space.