Photo: CC BY-SA 3.0, via Wikimedia Commons.The place
Sidewalks and shopfronts that ended up a story below the street.
The Seattle Underground is the name for a set of passages, former sidewalks and basements under the buildings and sidewalks of Pioneer Square. They are what remains of the neighborhood's original street level, which was raised after a disaster.
On June 6, 1889, a fire that began in a cabinet shop destroyed much of downtown and the waterfront. The district was mostly built of wood, and the fire spread quickly. Afterward the city required masonry construction in the commercial district, and it used the rebuilding to fix older problems: low ground near Elliott Bay, tidal flats, poor drainage and steep streets.
What happened here
Streets were raised, and the old level became basements.
In Pioneer Square the streets were lifted anywhere from a few feet to a full story. Retaining walls held the new road level, and the gap between those walls and the buildings stayed open under the sidewalks. These gaps are called areaways. At first people climbed ladders between the street and the building doors. Later, brick arches and glass vault lights, small panes set in the sidewalk above, brought daylight below. The glass later turned amethyst in color.
Owners knew the original ground floor would end up underground, so they left it plain and put the decoration on the new ground floor above. Businesses moved up, though some carried on below for a time. In 1907 the city condemned the Underground over fears of bubonic plague, two years before the Alaska-Yukon-Pacific Exposition. The spaces were left to decay or used for storage, and some were taken over for illegal uses.
Only a small part has been restored and made safe for visitors, and it can be seen only on guided tours. One tour company has run since 1965 from the Pioneer Building and neighboring buildings, passing disused storefronts, artifacts and tunnel entrances. A second company, started in 2013, explores other sections and offers themed tours, including a Queer History Tour.
Photos
Below and above the street.
A dim, brick-walled basement room with a wooden walkway in the Seattle Underground. CC BY-SA 3.0, via Wikimedia Commons.The Great Seattle Fire of 1889, with firefighters and hoses in a historic photograph. public domain, via Wikimedia Commons.Vault lights seen from below in the Seattle Underground, above pipes and a brick arch. Mark Hursh, CC BY-SA 3.0, via Wikimedia Commons.Aerial view of the Pioneer Square District in Seattle. Joe Mabel, CC BY-SA 3.0, via Wikimedia Commons.
Go and see it
Practical notes.
The Underground is beneath the Pioneer Square neighborhood of Seattle, so start at street level in Pioneer Square and join a guided tour. Tours and activities near Seattle Underground.
Only a small part of the Underground is restored and safe, and it is open to the public only on guided tours. Book ahead and check each company's current schedule.
Look up at the sidewalks in Pioneer Square, where vault lights can still be seen in the pavement on some streets.
The two tour companies cover different sections of the Underground, so they are not repeats of each other.
Pair it with a walk around Pioneer Square to see the masonry buildings that went up after the fire.
Sold by Viator. Prices and review counts checked on 09/09/2026. These tours cover the Seattle Underground. Check each one for its current route and schedule.
Questions people ask
Before you go.
What is the Seattle Underground?
It is the collective name for old sidewalks, areaways and building basements beneath Pioneer Square. They were left below when the streets were raised after the Great Seattle Fire of 1889.
Why were Seattle's streets raised?
After the 1889 fire, the city rebuilt in masonry and used the chance to fix low ground near Elliott Bay, poor drainage and steep grades. Streets in Pioneer Square rose by anywhere from a few feet to a full story.
Can you visit the Seattle Underground?
Yes, but only a small restored part, and only on guided tours. Two companies run them, one since 1965 and another since 2013, so check their current schedules.
Why did Seattle condemn the Underground?
In 1907 the city condemned it for fear of bubonic plague. The basements were left to decay or used for storage, and some were used for illegal purposes.
More to see
Around Seattle
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