Long admired for his Land Art installations made with natural materials in and from the environment, Andy Goldsworthy has been a big influence in the eco art movement despite the non-activist nature of his creations. Many of his works are temporal and change with the seasons, tides, exposure to sunlight, or other natural processes. Documentation of his works in their locations is the primary way for viewers to see the pieces. An excellent documentary on some of Goldsworthy’s works is called “Rivers and Tides,” see link below.