Seattle Underground field trip

I was invited to chaperone a field trip for my sister to the underground Seattle tour. Seattle was built on a sawdust landfill, and there were numerous problems throughout the 1800's with plumbing and sinkholes. So the main level of the city was later built to the level of the second floor. It's still sinking, but the first story is "underground" so it isn't noticeable. After the tour we walked around Pioneer Square and found the birthplace of the United Parcel Service, where there is a monument including a waterfall. The picture shows myself and my sister Penny at said monument.