The tour begins with a rousing introduction to Seattle in an old nightclub in Pioneer Square. Apparently some of the founding fathers were a bit...uh... corrupt. Whatever their faults, they were also colorful.
While delving into some of the early politics, our inital guide talked about the main reason Seattle has an underground - if you guessed that the citizens desired an indoor mall to avoid getting wet, you'd be close to the right motive. Some of the underground has been (and is still) used for commerce. However, the real reason was a simple matter of wanting indoor plumbing that worked efficiently. My fifth grader son was doubled over in practical hysterics as we were told stories of how Thomas A. Crapper, the man who invented the early toilet, hadn't considered how the changing tides in Seattle might make things flush up at certain times of the day.
After the tour intro, our big group was split into three small groups, and we were escorted into separate sections of the tour's underground, so things never got too crowded. Our guide was Rick, and we enjoyed his entire presentation. While the underground itself isn't really a lot to see, his telling of the history brought the place to life for us.
While not for young kids, I would highly suggest this tour for the whole family. However, if you have a hard time navigating stairs, you might have to skip it. There aren't any elevators.
Bottom line? A perfect blend of history and entertainment.