Although some might find this attraction gross, kids seem to almost always enjoy it, and anyone who passes by is welcome to add their own gum to the multi-colored collage.

Just as the name would imply, the Seattle Gum Wall is covered in thousands of pieces of chewing gum that have been placed on the side of the Post Alley's Market Theater (now Unexpected Productions) since the early 1990s. This interactive, fairly unique attraction makes for a great backdrop for photos and a quick stop along the way to some of the city's most popular destinations.

While Portland, Oregon, may claim to be the weirdest city on the northwest coast, Seattle is more often viewed as a tech and industry hub with an outdoorsy side. However, Seattle is a little bit quirky and has some pretty quirky attractions, including the Seattle Gum Wall located just outside the main entrance to Pike Place Market .

01 of 08 It's Been Gummy for Over 20 Years Byron Park/Eye Em / Getty Images The Seattle Gum Wall has been gathering gum since the early 1990s when people waiting for shows at nearby Unexpected Productions would stick gum to the wall and coins to the gum to pass the time. Although theater workers tried to keep the wall clean when this tradition first started to happen, the number of people who added to it daily overwhelmed the theater's cleaning capabilities. Soon, thousands of pieces of gum had been affixed to the wall and cleaning efforts were completely abandoned for over 20 years. While you won't see a lot of coins these days (except for the occasional freshly-stuck coin), you will definitely see a lot of gum.

02 of 08 It's About 50 Feet Long John & Lisa Merrill/Getty Images You might envision that the gum wall is just a small strip of wall next to a theater entrance, but gum is stuck to the walls along an alley for more than 50 feet. While most of the gum is within the average person’s arm reach, some can be impressively high up on the wall or located in obscure places. Additionally, several visitors have begun making "gum sculptures" a few inches (or feet) in front of the wall on the street, and you'll likely discover something new every time you visit.

03 of 08 It Was Only Cleared Off Once jin chu ferrer/Getty Images In November of 2015, the Pike Place Market Preservation and Development Authority stripped all gum from the wall and steam cleaned the brick underneath to help preserve it. The work took 130 hours, and 2,350 pounds of gum old and new were scraped away during the process. However, once the cleaning was done, visitors quickly began adding gum to the wall again. If you visit today, you might never guess the wall was cleaned at all. It’s as gummy and icky as ever—no one, apparently, can stop the gum from accumulating here.

04 of 08 It's Not Very Clean Charles Bowes/Eye Em / Getty Images Up until November 2015, the gum wall had never been cleaned, meaning there were more than 20 years of gum stuck to the brick facade. Before the cleaning, though, there were spots in the wall where the gum was several inches thick. As one might expect from a wall of used gum, the Seattle Gum Wall also doesn't smell that great—especially on hot summer days when the stench can become almost unbearable in this narrow alleyway.

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05 of 08 It's Covered in Germs Joel Carillet/Getty Images Speaking of cleanliness, the Seattle Gum Wall made a list of the top five germiest tourist attractions in 2009, second only to the Blarney Stone, which actually involves putting your lips onto a surface. However, people don’t generally put anything other than their fingertips on the Seattle Gum Wall, and if you see anyone kissing this wall, advise them to stop. Additionally, once you've left the Gum Wall's alley, you should consider washing your hands before continuing on your trek through Pike Market.

06 of 08 There Are Many Gummy Designs on the Wall Noah Kreyenhagen / © TripSavvy 2018 While many people opt to stick a wad of chewed gum to the wall, other folks get pretty creative with their contributions. You’ll see plenty of designs in the gum—people spelling their names or making peace signs, hearts, stars, and other designs. If you’re looking for a good photo op, look for one of these designs as it’s not every day you see a gum-constructed illustration. Additionally, many of these creative collections are often covered up over time as more visitors come to add their chewed gum to the wall.

07 of 08 It's Not Seattle's Only Weird Attraction Doug Rowan/Getty Images The gum wall is one of a handful of weird attractions in Seattle, but it’s probably the grossest. If the wall of gum just isn’t enough for you, also consider a visit to the Fremont Troll, the Fremont Rocket, or the actual communist statue of Lenin, which can all be found within walking distance of one another in Fremont.