<P> While this earlier work was mostly done in the deserts of the American west, the end of the 1970s and the beginning of the 1980s saw works moving into the public landscape . Artists like Robert Morris began engaging county departments and public arts commissions to create works in public spaces such as an abandoned gravel pit . Herbert Bayer used a similar approach and was selected to create his Mill Creek Canyon Earthworks in 1982 . The project served functions such as erosion control, a place to serve as a reservoir during high rain periods, and a 2.5 acre park during dry seasons . Lucy Lippard's groundbreaking book, on the parallel between contemporary land art and prehistoric sites, examined the ways in which these prehistoric cultures, forms and images have "overlaid" onto the work of contemporary artists working with the land and natural systems . </P> <P> The expanding term of environmental art also encompasses the scope of the urban landscape . Agnes Denes created a work in downtown Manhattan Wheatfield - A Confrontation (1982) in which she planted a field of wheat on the two - acre site of a landfill covered with urban detritus and rubble . The site is now Battery Park City and the World Financial Center: morphing from ecologic power to economic power . </P> <P> Electric art: In 1999, the Bulgarian artist Elena Paroucheva created a new concept for the electricity pylons of power lines . </P> <P> Alan Sonfist introduced the key environmentalist idea of bringing nature back into the urban environment with his first historical Time Landscape sculpture, proposed to New York City in 1965, and visible to this day at the corner of Houston and LaGuardia in New York City's Greenwich Village . Today Sonfist is joining forces with the broad enthusiasm for environmental and green issues among public authorities and private citizens to propose a network of such sites across the metropolitan area, which will raise consciousness of the key role that nature will play in the challenges of the 21st century . The sacredness of nature and the natural environment is often evident in the work of Environmental Artists . </P>

Describe three pieces in the art collection of the early cities. brainly