211 First Ave S
Seattle, WA 98104
Here's what WSDOT says about this center, "Milepost 31 is an award-winning information center that highlights the people and projects that shaped Pioneer Square, and provides an inside look at the SR 99 Tunnel Project. There, you'll find more than just construction photos and brochures. You’ll find history, artifacts and interactive exhibits designed to broaden your understanding of the land beneath you. You’ll explore the neighborhood’s changing landscape, from earth-moving efforts of the past to the massive tunnel project that will soon move State Route 99 underground and reconnect Pioneer Square to the waterfront."
11 a.m. to 5 p.m. Tuesday - Saturday; Open until 8 p.m. on the first Thursday of each month during the Pioneer Square Art Walk