I stayed in Seattle as a guest of Railbookers.com.au, Visit Seattle and the Fairmont Olympic Hotel, though I paid for my own airfare to the USA.
Yesterday I visited the oldest part of Seattle, its Pioneer Square neighbourhood.
Then I went one further, and visited the Old Old Seattle beneath its streets - the original waterfront neighbourhood that existed one storey lower over a century ago.
In the late 19th century, Seattle's waterfront district was a foul-smelling stretch of bars and brothels which sat on flats which were often flooded. When the Great Seattle Fire levelled the city in 1889, it created the perfect opportunity for renewal.
What happened next was a remarkable feat of engineering. Over several years, concrete retaining walls were built along the sides of roads, then filled in so the new street surfaces were one storey higher.
While this was happening, businesses traded as usual in newly constructed buildings at least two storeys high; accessible via narrow sidewalks running at ground level below each side of the raised roads.
Finally, the gap between street and building was covered with a new sidewalk at what would become the new ground level, and what had been ground-level storeys became basements.
Some of these fasinating subterranean chambers can be visited. I joined the regular tour of Beneath the Streets, the newest company to offer access.
As Beneath the Streets shares its premises beneath Cherry Street with the ghost tour company Spooked in Seattle, it has a macabre location in which to begin its tour:
After an explanation of underground Seattle's history, my guide Richard led me through adjacent rooms to an area where the original sidewalk ran beneath the street, and the retaining wall could still be seen:
After we explored this area, we headed out on the streets to see something of above-ground Seattle, including the bust of the Native American Chief Seattle (or Si'ahl) who gave his name to the city:
Richard also pointed out the numerous glass skylights which let light into the underground areas, the glass now having turned purple as it contained manganese:
Then we headed into the J&M Cafe and Cardroom, billed as Seattle's oldest bar:
From a door in the alleyway behind the bar, we were able to access its original ground level, now being used as a storage space. But it still had some remnant wallpaper and signage from its original use:
Along the street, we descended into our final chamber in underground Seattle. This time, it was a renovated space that's in use as a live comedy venue:
If you look carefully, you can make out some famous Seattle-ites in that last photo.
It was a fascinating tour, and it's intriguing to think that a whole layer of the city, once thronged with inhabitants, now lies mostly silent beneath its streets.
Beneath the Streets' underground Seattle tour is $15; make bookings at www.beneath-the-streets.com.