Kenilworth Aquatic Gardens

Kenilworth Park & Aquatic Gardens is a National Park Service site located in the north eastern corner of Washington, D.C., and the near Maryland state border. Nestled near the banks of the Anacostia River and directly west of the Baltimore–Washington Parkway, Kenilworth Park & Aquatic Gardens preserves a plethora of rare waterlilies and lotuses in the cultivated ponds near the river. The park also contains the Kenilworth Marsh, the largest remaining tidal marsh in Washington, D.C., and an adjacent recreational area.

Source: Wikipedia