
The Seattle Underground is a network of underground passageways and basements in the
Pioneer Square neighborhood of
Seattle, Washington
Seattle ( ) is the List of municipalities in Washington, most populous city in the U.S. state of Washington (state), Washington and in the Pacific Northwest region of North America. With a population of 780,995 in 2024, it is the List of Unit ...
, United States. They were located at ground level when the city was built in the mid-19th century but fell into disuse after the streets were elevated. In recent decades, they have become a tourist attraction, with guided tours taking place around the area.
History

At approximately 2:20 p.m. on June 6, 1889, an overturned glue pot in a carpentry shop accidentally started the most destructive fire in the history of Seattle. After this
Great Seattle Fire, new construction was required to be of masonry, and the town's streets were
regraded one to two
stories higher.
Pioneer Square had originally been built mostly on filled-in
tidelands
Tidelands are the territory between the tide line of sea coasts and lands lying under the sea beyond the low-water limit of the tide, considered within the territorial waters of a nation.
In the United States, the upper limit of tidelands is ...
and often
flood
A flood is an overflow of water (list of non-water floods, or rarely other fluids) that submerges land that is usually dry. In the sense of "flowing water", the word may also be applied to the inflow of the tide. Floods are of significant con ...
ed. The new street level also kept sewers draining into
Elliott Bay
Elliott Bay is a part of the Central Basin region of Puget Sound. It is in the U.S. state of Washington, extending southeastward between West Point in the north and Alki Point in the south. Seattle was founded on this body of water in the 1850s ...
from backing up at
high tide
Tides are the rise and fall of sea levels caused by the combined effects of the gravitational forces exerted by the Moon (and to a much lesser extent, the Sun) and are also caused by the Earth and Moon orbiting one another.
Tide tables ...
.
For the regrade, the streets were lined with concrete walls that formed narrow alleyways between the walls and the buildings on both sides of the street, with a wide "alley" where the street was. The naturally steep hillsides were used and, through a series of
sluice
A sluice ( ) is a water channel containing a sluice gate, a type of lock to manage the water flow and water level. There are various types of sluice gates, including flap sluice gates and fan gates. Different depths are calculated when design s ...
s, material was washed into the wide "alleys", by raising the streets to the desired new level, generally higher than before, in some places nearly .
At first, pedestrians climbed ladders to go between street level and the sidewalks in front of the building entrances. Brick archways were constructed next to the road surface, above the submerged sidewalks.
Vault lights (a form of walk-on skylight with small panes of clear glass which later became
amethyst-colored) were installed over the gap from the raised street and the building, creating the area now called the Seattle Underground.

When they reconstructed their buildings, merchants and landlords knew that the ground floor would eventually be underground and the next floor up would be the new ground floor, so there is very little decoration on the doors and windows of the original ground floor, but extensive decoration on the new ground floor.
Once the new sidewalks were complete, building owners moved their businesses to the new ground floor, although merchants carried on business in the lowest floors of buildings that survived the fire, and pedestrians continued to use the underground
sidewalk
A sidewalk (North American English),
pavement (British English, South African English), or footpath (Hiberno-English, Irish English, Indian English, Australian English, New Zealand English) is a path along the side of a road. Usually constr ...
s lit by the vault lights (still seen on some streets) embedded in the grade-level
vaulted sidewalk above.
In 1907, the city condemned the Underground for fear of
bubonic plague
Bubonic plague is one of three types of Plague (disease), plague caused by the Bacteria, bacterium ''Yersinia pestis''. One to seven days after exposure to the bacteria, flu-like symptoms develop. These symptoms include fever, headaches, and ...
, two years before the 1909 World Fair in Seattle (
Alaska-Yukon-Pacific Exposition). The basements were left to deteriorate or were used as storage. Some became illegal
flophouses for the
homeless
Homelessness, also known as houselessness or being unhoused or unsheltered, is the condition of lacking stable, safe, and functional housing. It includes living on the streets, moving between temporary accommodation with family or friends, liv ...
,
gambling
Gambling (also known as betting or gaming) is the wagering of something of Value (economics), value ("the stakes") on a Event (probability theory), random event with the intent of winning something else of value, where instances of strategy (ga ...
halls,
speakeasies
A speakeasy, also called a beer flat or blind pig or blind tiger, was an illicit establishment that sold alcoholic beverages. The term may also refer to a retro style bar that replicates aspects of historical speakeasies.
In the United State ...
, and
opium dens.
Tours
Only a small portion of the Seattle Underground has been restored and made safe and accessible to the public on guided tours.
In 1965, local citizen
Bill Speidel
William C Speidel (February 11, 1912 – May 3, 1988) was a columnist for ''The Seattle Times'' and a self-made historian who wrote the books ''Sons of the Profits'' and ''Doc Maynard, The Man Who Invented Seattle'' about the people who settled and ...
formally created "Bill Speidel's Underground Tour", which continues to operate from the
Pioneer Building and adjacent buildings. The tour route passes disused storefronts, artifacts, and multiple tunnel entrances.
A second tour company, Beneath the Streets, was created in 2013 and explores different sections of Seattle's Underground network. In addition to its standard tour, Beneath The Streets offers specialized experiences, including a ''Queer History Tour'', highlighting the LGBTQ+ community's impact on the city's development, and a ''Red Light District Tour'', which delves into the district's vibrant and complex past.
See also
*
Catacombs of Paris
The Catacombs of Paris (, ) are underground ossuaries in Paris, France, which hold the remains of more than six million people. Built to consolidate Paris's ancient stone quarries, they extend south from the ("Gate of Hell") former city gate. ...
*
Catacombs of Rome
The Catacombs of Rome () are ancient catacombs, underground burial places in and around Rome, of which there are at least forty, some rediscovered since 1578, others even as late as the 1950s.
There are more than fifty catacombs in the underg ...
*
Edinburgh Vaults
*
Mary King's Close
*
Manchester Cathedral Steps
*
Raising of Chicago
*
Shanghai tunnels (less commonly known as the Portland Underground, in
Portland, Oregon
Portland ( ) is the List of cities in Oregon, most populous city in the U.S. state of Oregon, located in the Pacific Northwest region. Situated close to northwest Oregon at the confluence of the Willamette River, Willamette and Columbia River, ...
)
*
Underground Atlanta
Underground Atlanta is a shopping center, shopping and entertainment district in the Five Points, Atlanta, Five Points neighborhood of Downtown Atlanta, downtown Atlanta, Georgia, United States, near the Five Points (MARTA station), Five Points ...
*
Underground City, Montreal
RÉSO, commonly referred to as the Underground City (), is the name applied to a series of interconnected office towers, hotels, shopping centres, residential and commercial complexes, convention halls, universities and performing arts venues tha ...
, modern construction of interconnected office buildings, hotels, shopping centers and other venues in
Montreal
Montreal is the List of towns in Quebec, largest city in the Provinces and territories of Canada, province of Quebec, the List of the largest municipalities in Canada by population, second-largest in Canada, and the List of North American cit ...
's
CBD
*
Underground City
An underground city is a series of linked subterranea (geography), subterranean spaces that may provide a defensive refuge; a place for living, working or shopping; a transit system; mausoleum, mausolea; wine or storage cellars; cisterns or dra ...
(underground features in cities around the world)
References
Further reading
*
*
External links
*
Mashable: 1905-1930 The Seattle Regrade
{{Man-made and man-related Subterranea
Underground
Tourist attractions in Seattle
Underground cities