About Seattle Underground
Seattle has another Seattle underneath it. Beneath portions of Pioneer Square are old sidewalks, storefronts, doorways, and building spaces left behind when the city rebuilt its streets at a higher level after the Great Seattle Fire of 1889.
The fire destroyed a large portion of the business district. During reconstruction, officials addressed drainage and flooding problems by raising the street grade. New roads and sidewalks were built above the old level, while businesses gradually moved their public entrances upward.
That process left strange voids underneath the new city. Old first-floor spaces became basements, buried sidewalks became passageways, and architectural details designed for daylight ended up underground. Some of those surviving spaces eventually became accessible through guided tours.
Bill Speidel began public Underground Tours in 1965, helping preserve both the physical spaces and public interest in them. Visitors now walk through a city layer that was not excavated from ancient ruins. Seattle simply built a newer street system on top of the old one and left enough behind to explore.