Washington Monument located in protected area National Mall
The Washington Monument is an obelisk-shaped building, on the National Mall in Washington, D.C., built to commemorate George Washington, a Founding Father of the United States, victorious commander-in-chief of the Continental Army from 1775 to 1784 in the American Revolutionary War, and the first President of the United States from 1789 to 1797. Standing east of the Reflecting Pool and the Lincoln Memorial, the monument, made of marble, granite, and bluestone gneiss, is both the world's tallest predominantly stone structure and the world's tallest obelisk, standing 554 feet 7+11⁄32 inches (169.046 m) tall, according to the U.S. Geodetic Survey measurements in 2013–2014.  It is the tallest monumental column in the world if all are measured above their pedestrian entrances. It was the world's tallest structure between 1884 and 1889, after which it was overtaken by the Eiffel Tower, in Paris. Previously, the tallest structure was the Cologne Cathedral. 
Construction of the presidential memorial began in 1848. The construction was suspended from 1854 to 1877 due to funding challenges, a struggle for control over the Washington National Monument Society, and the American Civil War. The stone structure was completed in 1884, and the internal ironwork, the knoll, and installation of memorial stones was completed in 1888. A difference in shading of the marble, visible about 150 feet (46 m) or 27% up, shows where construction was halted and later resumed with marble from a different source. The original design was by Robert Mills from South Carolina, but construction omitted his proposed colonnade for lack of funds, and construction proceeded instead with a bare obelisk. The cornerstone was laid on July 4, 1848; the first stone was laid atop the unfinished stump on August 7, 1880; the capstone was set on December 6, 1884; the completed monument was dedicated on February 21, 1885; and opened October 9, 1888.
The Washington Monument is a hollow Egyptian-style stone obelisk with a 500-foot (152.4 m) tall column surmounted by a 55-foot (16.8 m) tall pyramidion. Its walls are 15 feet (4.6 m) thick at its base and 1+1⁄2 feet (0.46 m) thick at their top. The marble pyramidion's walls are 7 inches (18 cm) thick, supported by six arches: two between opposite walls, which cross at the center of the pyramidion, and four smaller arches in the corners. The top of the pyramidion is a large, marble capstone with a small aluminum pyramid at its apex, with inscriptions on all four sides. The bottom 150 feet (45.7 m) of the walls, built during the first phase from 1848 to 1854, are composed of a pile of bluestone gneiss rubble stones (not finished stones) held together by a large amount of mortar with a facade of semi-finished marble stones about 1+1⁄4 feet (0.4 m) thick. The upper 350 feet (106.7 m) of the walls, built in the second phase, 1880–1884, are of finished marble surface stones, half of which project into the walls, partly backed by finished granite stones.The interior is occupied by iron stairs that spiral up the walls, with an elevator in the center, each supported by four iron columns, which do not support the stone structure. The stairs are in fifty sections, most on the north and south walls, with many long landings stretching between them along the east and west walls. These landings allowed many inscribed memorial stones of various materials and sizes to be easily viewed while the stairs were accessible (until 1976), plus one memorial stone between stairs that is difficult to view. The pyramidion has eight observation windows, two per side, and eight red aircraft warning lights, two per side. Two aluminum lightning rods, connected by the elevator support columns to groundwater, protect the monument. The monument's present foundation is 37 feet (11.3 m) thick, consisting of half of its original bluestone gneiss rubble encased in concrete. At the northeast corner of the foundation, 21 feet (6.4 m) below ground, is the marble cornerstone, including a zinc case filled with memorabilia. Fifty American flags fly on a large circle of poles centered on the monument. In 2001, a temporary screening facility was added to the entrance to prevent a terrorist attack. An earthquake in 2011 slightly damaged the monument, and it was closed until 2014. The monument was closed for elevator repairs, security upgrades, and mitigation of soil contamination in August 2016 before reopening again fully in September 2019.
situated in conservation area found in preserved zone positioned in restricted site placed in secured territory situated in sheltered region