The Washington Monument remains `` structurally sound '' and is `` not going anywhere , '' a top National Park Service official said Monday , announcing the result of a comprehensive assessment of the structure 's interior . A five-day examination of the monument 's exterior will begin Tuesday , according to Bob Vogel , superintendent of the National Mall and Memorial Parks . Four cracks in the monument 's marble were discovered shortly after a 5.8-magnitude earthquake struck the East Coast on August 23 . The monument has since been closed to the public . Officials declined to say Monday when the monument will re-open . Small pools of standing water were found in the monument during inspections following Hurricane Irene , the National Park Service said in late August . `` What happened was a lot of mortar popped out , so much so that you can see sunlight above 450 feet in the monument , '' spokeswoman Carol Johnson said at the time . The National Park Service has been working with an engineering firm to determine the extent of the damage and what it will cost to fix it . Repairs will include pinning several stones together and replacing some mortar , Johnson noted . The Washington Monument , built between 1848 and 1884 , is 555 feet , 5 and one-eighth inches tall . Its walls are 15 feet thick at the base and 18 inches at the top , and are composed primarily of white marble blocks , according to the National Park Service .
The Washington Monument is declared ` ` structurally sound '' Officials decline to say when the monument will re - open to the public . Cracks were discovered after an earthquake in late August ; repairs are required . The Washington Monument is 100 feet tall .