Tolga Akmen/LNP/REX/ShutterstockEvery five years or so, crew members scale the 316-foot-tall clock to scrub its four timepieces, each containing 312 pieces of opal glass. And time doesn’t stop: Workers dodge the moving minute and hour hands, which measure nearly 14 and nine feet long, respectively! The next scheduled cleaning is in the 2020s. Before you book a flight to see it, these are the 13 things airlines don't want you to know.
PABLO MARTINEZ MONSIVAIS/AP/REX/ShutterstockTwice a year, Honest Abe gets blasted with a powerful pressure washer. (Did you know there's a typo on the Lincoln Memorial?) National Park Service workers then use massive makeshift cotton swabs to clean bugs and bird droppings from his ears. Don't miss these timeless Abraham Lincoln quotes.
TGurgen Bakhshetyan/shutterstockIt takes 10,000 doses of cleaning product, four tons of cleaning rags, and 25,000 trash bags to polish the Parisian landmark. Workers do it once a year. These are the French phrases (and how to pronounce them!) that everyone should know.
Acropolis Hill sculptures
Olga Kot Photo/shutterstockIn 2008, scientists set out to find the safest way to swab the 2,500-year-old marble statues. After testing 40 methods, they determined the winning technique was a combination of infrared lasers and ultraviolet rays. But the cleaning can be a dangerous job: Restorers wear goggles and operate the lasers for only two hours a day.
Statue of Liberty
Usa Pyon/shutterstockLady Liberty has dodged bath time for a while now—curators haven’t cleaned her exterior in years because infrequent cleaning aids in her preservation. (Don't miss these 20 extraordinary facts about the Statue of Liberty.) The inside gets scrubbed frequently, however, which is how the statue developed “birthmarks”—an acidic solution leaked through the inside wall and stained her cheek in 1986.
The Trevi Fountain
MAURIZIO BRAMBATTI/EPA/REX/ShutterstockFor decades, tourists have tossed coins into Rome's Trevi Fountain to ensure a return trip to the city—and they're not inclined to stop on the days the fountain's being cleaned. In order to restore the Baroque monument in 2014, a temporary bridge had to be built so visitors could get a good look at the fountain's sculptures and toss coins into a basin in front of it. Those who didn't want to wait in line could toss a coin into a mini replica of the fountain, which was also constructed to satisfy visitors during the yearlong restoration.
Jeff Schultes/REX/ShutterstockCleaning this historic spot requires tons of prep. For one, there's no nearby water supply and no roads go its the top. Instead, cleaning crews must fly equipment to the top of the mountain in a helicopter, and have local fire engines pump water through huge pipes. These are the best free tourist attractions in each state.