Site-specific art is a term referring to works of art created with a view to functioning strictly in a particular place for a particular location, environment, landscape, a specific and peculiar space. It is deeply contextual, so in regard to the issue of the protection of a historic city, one can ask about its role and scope of creation as a condition for its sustainable development. What is meant by sustainable development? And how to perceive the thought of the great Aquinas, referring to the concept of Creatio (gr.), an act of creative action, bringing some existence to life and keeping it alive – the basic principle of conservation. Let us try to confront the experimental language of contemporary artists with Gombrich’s theory of time-cultural relativism, the meaning of the genius loci of the place, based on sources and our own educational and artistic experience.