<Tr> <Td> </Td> <Td> This article needs additional citations for verification . Please help improve this article by adding citations to reliable sources . Unsourced material may be challenged and removed . (October 2009) (Learn how and when to remove this template message) </Td> </Tr> <P> The Lincoln Memorial Reflecting Pool is the largest of the many reflecting pools in Washington, D.C., United States . It is a long and large rectangular pool located on the National Mall, directly east of the Lincoln Memorial, with the Washington Monument to the east of the reflecting pool . Part of the iconic image of Washington, the reflecting pool hosts many of the 24 million visitors a year who visit the National Mall . It is lined by walking paths and shade trees on both sides . Depending on the viewer's vantage point, it dramatically reflects the Washington Monument, the Lincoln Memorial, the Mall's trees, and / or the expansive sky . </P> <P> The Lincoln Memorial Reflecting Pool was designed by Henry Bacon, and was constructed in 1922 and 1923, following the dedication of the Lincoln Memorial . It is approximately 2,029 feet (618 m) long (over a third of a mile) and 167 feet (51 m) wide . The perimeter of the pool is therefore 4,392 feet (1,339 m), about 0.83 miles around . It has a depth of approximately 18 inches (46 cm) on the sides and 30 inches (76 cm) in the center . It holds approximately 6,750,000 U.S. gallons (25,500,000 L) of water . </P> <P> Using funding from the American Recovery and Reinvestment Act of 2009, the National Park Service reconstructed the Lincoln Memorial Reflecting Pool . The pool's water supply system was updated to eliminate stagnant water by circulating water from the Tidal Basin; the pool was formerly filled using potable water from the city . Paved walking paths were added to the north and south sides of the pool to replace worn grass and to prevent further erosion . Construction on the 18 - month, $30.74 million project began in November 2010 . In May 2011, workers began sinking the first of 2,113 wood pilings into a 40 - foot deep layer of soft, marshy river clay and some dredged material atop bedrock to support a new pool . The pool reopened on August 31, 2012 . The project was managed by the Louis Berger Group . </P>

When was the reflecting pool in washington dc built