The Japanese Garden in Van Nuys is a carefully composed retreat of dry Zen garden, tea garden, lakes, streams, and waterfalls. It is attached to the Donald C. Tillman Water Reclamation Plant, and the reclaimed-water setting is part of what makes the place unusual.
Come for a quiet walk rather than a big Los Angeles spectacle. The garden is especially good if you are already in the San Fernando Valley and want something calmer than the city's usual museum-and-studio circuit.