George Washington Memorial Parkway is more than just an attractive roadway. The original commemorative function remains strong, as civic and military memorials continue to be added to the parkway landscape. These range from traditional bronze statues such as "Iwo Jima" and the monuments lining the approach to Arlington Cemetery to abstract modernist sculptures and groves of memorial trees. The parkway also offers a variety of recreational opportunities. Its picnic areas and marinas continue to be enormously popular with tourists and locals alike. A multi-use trail was built between Washington and Mount Vernon in the 1970s and extended north to Rosslyn in the 1980s. As a wildlife refuge, the parkway serves as a permanent or temporary home to a wide variety birds and mammals. The parkway also preserves many important historical features, including Washington's Patowmack Canal, Arlington House, and the remains of several Civil War forts.