the fountain is located in the southwest corner of hyde park, just south of the serpentine lake and east of the serpentine gallery. its cornerstone was laid in september 2003 and it was officially opened on 6 july 2004 by queen elizabeth ii. also present were diana's younger brother charles spencer, her ex-husband prince charles, and her sons william and harry, her ex-father in law prince philip, duke of edinburgh and her two sisters lady jane fellowes and lady sarah mccorquodale . the opening ceremony brought the windsors and the spencers together for the first time in 7 years.