viaduct

For the past four years, from Sodo to South Lake Union, a 9,270-foot underground dig has unfolded to bring Seattle the world’s largest tunnel, part of the $3.1 billion replacement of the Alaskan Way Viaduct. The tunnel ($2 billion of that), while beset by not-inconsiderable setbacks, is also a project marked by engineering marvels on a Brobdingnagian scale. Take an underground tour with our exclusive photo essay.

While politicians, judges and activists argue over all things tunnel, planners are busily imagining what a post-Viaduct Seattle waterfront will look like.