Downstream of Alexandria, the river continues to widen and the salinity increases. Here the river becomes wilder with less visible development along the shores, more wetlands and expansive coves and inlets. Jones Point Lighthouse is provides a visual reminder of the Potomac's past importance as a commercial shipping center carrying tobacco and other agricultural products to other U.S. ports and Europe.
Further along the river, the Dyke Marsh is one of the best birding areas in the D.C. area and a reminder of what much of the Washington area's shoreline looked like before development so drastically effected our shorelines.
The Dyke Marsh stretches along the George Washington Memorial Parkway. It is one of the most important wetlands in the greater Washington area. The grasses and flats are filled with wildlife, making it a popular destination among birders and weekend naturalists. Well over 250 species of birds have been documented as visiting or year round residents. In many ways, the marsh provides a glimpse of what much of the Greater Washington area's riverfront looked like during colonial times. Over the years, most of the wetlands in the area have been filled in and drained as the shoreline was developed. Today the marsh still offers us the opportunity to see herons, wrens, ducks, geese, hawks and host of other birds within a few miles of Old Town Alexandria and the Wilson Bridge.
Across from Belle Haven are Fort Foote and Fort Washington. Both were sited on high bluffs to offer commanding views of the river, and were constant threats to hostile ships heading for Washington.
At the start of the Civil War, the City of Washington was protected only by Fort Washington. Confederate troops were stationed in Northern Virginia. The Union hastily established a ring of 68 forts around Washington to protect the city. Fort Foote was the largest and southernmost of the forts.