Seattle Underground Guided Walking Tour beneath Pioneer Square

Pioneer Square, Seattle's oldest neighbourhood

Pioneer Square is where Seattle began in 1852, when settlers built a sawmill and cabins on a narrow strip of land between the hills and the tideflats of Elliott Bay. Logs were slid down a steep street to the mill, and the neighbourhood around it grew into a rough, busy port town. Today its streets are lined with red-brick and stone buildings in the Romanesque Revival style, galleries, bookshops and cafés, and a graceful cast-iron pergola from 1909 shelters the small triangular square.

In 1897 the area became the outfitting centre for gold seekers heading to the Klondike, a story told in the free national historical park museum on South Jackson Street. A Pioneer Square walking tour starts naturally here, and the underground tour adds the hidden layer below. The neighbourhood is a short walk from the ferry terminal and the waterfront, and next to the Pioneer Square light rail station.

The Great Seattle Fire of 1889

On 6 June 1889, a pot of glue boiled over in a woodworking shop near First Avenue and Madison Street. The flames spread through the wooden buildings, and with low water pressure the fire burned for most of the day, destroying some 25 city blocks, including almost the whole business district and the wharves. Remarkably, no human deaths were recorded.

Your guide tells how the disaster became an opportunity. The city ruled that new buildings in the centre must be built in brick or stone, which is why Pioneer Square looks so uniform today, and it decided to fix the drainage problems of the low, muddy ground at the same time. This rebuilding created the passageways you walk through on the tour.

Raising the streets: how Seattle Underground was created

Old Seattle stood so low that the tide pushed water back up the drains, and the streets turned to mud in winter. After the fire the city built stone retaining walls along each street and filled the space between them, lifting the roadways by one to two storeys. Shop owners, however, had already rebuilt at the old level, so for several years people climbed ladders between the new streets and the old sidewalks.

Eventually the gaps were roofed over with new pavements, and the old sidewalks and ground-floor shopfronts disappeared beneath them, becoming the underground. Glass prisms set into the pavement let daylight into the passages; many have turned lavender with age. After the city condemned the underground in 1907, these spaces were left to storage and decay until they were rediscovered decades later.

The underground passageways today

On this Seattle Underground walking tour you descend into three passageways and see the original sidewalks, the faded facades and doorways of shops, the thick retaining walls and timber beams that hold up the streets above. From below, the skylight prisms glow like small purple windows. Some old signs and objects found during clearance are displayed along the route.

Between the passageways you walk above ground through Pioneer Square, so the tour is part outdoors and part underground, with six flights of stairs in total and no lift. The passages are dim, cool and dusty, with uneven floors, which adds to the atmosphere. The guide keeps the group together and the stories lively, so the hour passes quickly.

Is the Seattle Underground tour worth it? Practical tips

For most visitors the answer is yes: in one hour you understand how the city was built and see a part of it that is hidden from the street, which makes it one of the most popular things to do in Seattle on a rainy day. Underground Seattle tickets can sell out at weekends and in summer, so booking ahead is wise.

The best time is a weekday morning or mid-afternoon, when groups are smaller. Wear comfortable shoes with good grip and bring a light jacket, as part of the walk is outside. The tour combines well with the waterfront, the ferry ride across Elliott Bay or a visit to Pike Place Market, about 15 minutes north on foot.