Seattle Asian Art Museum
1400 E Prospect St, Seattle, Washington
100% positive
Directions: Downstairs near elevator. The elevator is in a weird spot - inside their tiny gift shop. You do need to be a visitor but, if you can't afford admission, ask for the Museums for All entry.
Comments: I don't know that it doesn't have a changing table. It might. I just didn't notice. Spacious, beautiful multistall bathroom, long stall doors ensure privacy. Two entrances, both gender-free.