More than two and a half years after sustaining serious damage in an earthquake, the Washington Monument reopened to the public on Monday.
The 5.8-magnitude quake in August 2011 caused 150 cracks in the 555-foot marble obelisk that cost $15 million to repair. Tours will resume at 1 p.m.
In honor of the 130-year-old monument's restoration, here are 15 facts you may or may not know about the symbolic structure.
• The Washington Monument was the world's tallest building when it was completed in 1884, surpassing the 515-foot Cologne Cathedral. In 1889, the monument was eclipsed by the 1,063-foot Eiffel Tower, but remains the world's tallest freestanding stone structure.
• The monument is the tallest building in Washington and is likely to stay that way, given laws restricting the height of buildings. The 1899 Height of Buildings Act "established that no building could be taller than the Capitol (289 feet)," says a post on WeLoveDC.com. "In 1910 the act was amended to restrict building heights even further: no building could be more than twenty feet taller than the width of the street that it faces. So, a building on a street with an 80-foot right-of-way could only be 100 feet, or 10 stories."
• Forget about the height. The width at its base is more than 55 feet, with walls 15 feet thick. At the top of the shaft, the width is more than 34 feet, with 18-inch walls.
• The monument — designed by architect Robert Mills and eventually completed by Thomas Casey and the U.S. Army Corps of Engineers — was built in two phases of construction: 1848-1854 and 1876-1884. The 22-year delay was caused by a lack of private funding, political posturing and the American Civil War.
• It was built in the shape of an Egyptian obelisk, "evoking the timelessness of ancient civilizations" and embodying "the awe, respect, and gratitude the nation felt for its most essential Founding Father."
• The cornerstone of the monument was laid on July 4, 1848, with 20,000 people in attendance. Among them: President James K. Polk, Dolley Madison (wife of President James Madison), Elizabeth Hamilton (wife of Alexander Hamilton), George Washington Parke Custis (George Washington's step-grandson) and future presidents James Buchanan, Abraham Lincoln, and Andrew Johnson.
• Total number of blocks in monument: 36,491. Total weight: more than 80,000 tons.
• Three types of stone from two different quarries were used to construct the monument. They were the same color when it was completed, but have weathered differently, resulting in a change in color on the exterior.
• There are 193 commemorative stones lining the walls of the monument.
• The stairwell contains 897 steps, but they are closed to the public, mostly to prevent vandalism.
• The elevator trip to the top of the monument is approximately 70 seconds. The original steam-driven elevator took up to 12 minutes.
• Despite reports from visitors, the Washington Monument does not sway in the wind. "Because it is an all-stone structure, the building cannot bend and move the way a steel skyscraper can," the National Park Service says. "Most of the movement visitors detect is from the floor shaking from other people walking around and the elevator vibrations."
• Congress allocated $7.5 million in public funds for half of the monument's restoration. The other half was donated by philanthropist David Rubenstein.
• Even the construction of the aluminum cap on the Washington Monument was historic. Edgar H. Dix, then chief metallurgist of the Aluminum Company of America, once called it "the crown jewel of the aluminum industry."
• Inscribed on the aluminum cap are the Latin words "Laus Deo." Translation: "Praise be to God.