The McMillan Sand Filtration Site is a decommissioned water treatment plant, a twenty-five acres of green space and an abandoned and endangered historic landmark (Most Endangered Properties in 2000 and 2005). The tower-like sand bins and lawns were designed by Frederick Law Olmsted, Jr., landscape architect; Allen Hazen, engineer; and Charles Platt, architect. This wonderful infrastructure was a direct legacy of the City Beautiful Movement and part of the McMillan Plan to modernize the city back in 1902.

With some public attention, the McMillan Sand Filtration Site could become a viable open space with public amenities including a museum (with its catacomb-like underground cells), multi-purpose play fields, and iconic ruins, similar to the ones found at Northside Park in Denver, Colorado, and Gas Works Park in Seattle, Washington.