Lurie Garden is a 2.5-acre (10,000 m²) garden located at the southern end of Millennium Park in the Loop area of Chicago in Cook County, Illinois, United States. Designed by Kathryn Gustafson, Piet Oudolf, and Robert Israel, it opened on July 16, 2004. The garden is a combination of perennials, bulbs, grasses, shrubs and trees. It is the featured nature component of the world's largest green roof. The garden cost $13.2 million and has a $10 million endowment for maintenance and upkeep. It was named after Ann Lurie, who donated the $10 million endowment.