Making public spaces sustainable as well as entertaining is a major challenge of modern urban design. Philadelphia aka Philly aka &lsquoThe City of Brotherly Love&rsquo scores on both counts. Dilworth Park, launched in September, is a sustainable green public space. The park, after its renovation, has 20,571 sq. ft of new useable area. The central feature of Dilworth Park is an 11,600 sq. ft computer-programmable fountain, fed with recycled rainwater. The fountain is covered by a thin scrim of water, with three-foot-high spouts creating a dancing water feature &ndash great fun for children. During winter, this fountain surface will become an ice skating rink, making Dilworth Park worth visiting all year.