Madrona Marsh is a 43-acre vernal freshwater wetland preserve at the corner of Plaza del Amo and Madrona, a small remnant of the seasonal marshes that once covered much of the LA basin. It is one of the last surviving vernal pool habitats in southern California — flooded in winter and spring, dry by late summer.
The site is open as a wildlife preserve with a small nature centre, walking trails, and birding hides. Migratory ducks, herons, dragonflies, and the occasional coyote use the marsh; over 250 bird species have been recorded here. Free entry; the nature centre runs guided walks at weekends.