Located on tidal marshland along the eastern bank of the Anacostia River, this peaceful natural spot in northeast Washington comprises numerous diked lakes devoted to the cultivation of water lilies, lotus and other aquatic plants. A brochure on the gardens, with a map of the ponds, is available at the visitor center. Bear in mind that the flowers are more spectacular in the morning. Seasonal highlights: water lilies in June and July; tropical plants in July and August.