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Photo: The original uploader was Ser Amantio di Nicolao at English Wikipedia., CC BY-SA 3.0 via Wikimedia Commons
One of the largest remaining pieces of freshwater tidal wetlands left in the DC area, accessible by a short hiking trail
Dyke Marsh is a freshwater wetland and wildlife preserve located on the west bank of the Potomac River south of Alexandria, Virginia between Old Town Alexandria and Mount Vernon. Dyke Marsh consists of about 380 acres (1.5 km2) of tidal marsh, floodplain, and swamp forest. It formed 5,000 to 7,000 years ago. With a total size of 485 acres, Dyke Marsh is one of the largest remaining pieces of freshwater tidal wetlands left in the Baltimore-Washington Metropolitan Area. The marsh is managed by the National Park Service as part of the George Washington Memorial Parkway. Dyke Marsh contains a wide array of plant and animal life. "Haul Road" is a trail that leads visitors into the marsh. It is frequented by area birdwatchers. Dyke Marsh is located off the George Washington Memorial Parkway at the Belle Haven Marina exit.
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A historic mansion that is headquarters of the American Horticultural Society. The grounds are open to the public, and there is a garden shop.
A 19th-century plantation house
An oasis of wilderness in the middle of suburban sprawl, notable for the amount and variety of wildlife that congregates there. Features a large beaver lake with a boardwalk constructed across it. Popular with bird-watchers.
Popular with joggers and picnickers, the park holds defensive batteries from the former army installation, the exterior of which can be explored.
George Washington's Mount Vernon Estate and Gardens; has its own article