This wall is near Pike's Place Market. Not all the local folks knew where it was when we asked around. But it does exist, and it is SO GROSS. It's just a brick wall where people stick their gum. Some people spell stuff, some people string their gum across other gum, and some people throw their gum way up high to try to make it stick up there.
A girl walking away from the wall as we arrived was chewing gum and I was like, "free gum? Awesome!"