PORTLAND, Ore. — Directly across the Willamette River from this city’s downtown, a small area called Burnside Bridgehead is transforming, in a microcosm of what is happening throughout the city.

Across the four city blocks, several large multiuse sites are under construction in the once-gritty part of town. Artists and other urban pioneers have over the last several years turned the surrounding area into a destination, paving the way for star chefs and luxury apartments.

Portland — Oregon’s largest city, with over 600,000 residents — has been evolving with an artistic bent over the last decade. One east-side project, though, stands out as embodying Portland’s knack for keeping things weird, even as it gentrifies: the building known as Fair-Haired Dumbbell.

The “dumbbell” in the name comes from the project’s design — two six-story buildings connected by sky bridges — to which was added “fair-haired” as a play on “redheaded stepchild,” something neglected or maligned.