I woke up this morning complaining my internet was running slow till I saw this picture then I realized that was nothing to complain about.
Those "spots" in the sidewalk are actually glass inserts that let light shine in the underground tunnels that ran throughout the sales/commercial district of Portland, serving businesses from boats along the seawall on the Willamette River. Quite a few "Shanghai's" occurred along there, too.
I remember my parents bought a new Bug from them in 1968. I think it was the worst car they ever owned. They traded in mom's 63 Comet S-22 we had at the time. It was a very sad day. I think there's a Toyota dealership there now.