In July 2004, the Queen came to Hyde Park to open a beautiful gated fountain designed to conjure the memory of the mother of her grandchildren and a longtime thorn in her side, Princess Diana. As designed by American architect Kathryn Gustafson, this graceful O-shaped fountain undulates down a gentle slope, sending two flumes of water gurgling into a collecting pool. At three points, bridges carry you to the center. A day after the opening, trouble began. It clogged with leaves. Then visitors started slipping on algae. So it closed for 5 months while an asphaltlike path was laid around it, spoiling the effect. After it re-opened, hairline cracks were found in its 545 blocks of Cornish granite. The bill for that? £5.2 million. Londoners decided they don’t miss Di that much. Rather than putting you in a state of remembrance, it may put you into a state of wanting to ride it on an inner tube. Reach it from the Alexandra Gate at Kensington Gore, Knightsbridge, up Exhibition Road, and don’t confuse it for the Diana, Princess of Wales Playground in Kensington Gardens.