Fascinating trip into the beginnings of Seattle. The tour is both underground and topside for some time. A lot of the rooms underground are empty, what you see are the architectural form (and some sneaky built-ins), but the tour includes many pictures that are incredible showing what happened and the changes. Our tour guide, Kieran, was very knowledgeable and took the time to answer all our questions (even though we ran over time a little!). Each tour builds on the other, no two tours are the same. If you like history, this is a great tour to take.