In 1977, the International Council of Museums declared May 18 International Museum Day. Two local museums, SAM and Seattle Asian Art Museum are participating by offering free admission.
From SAM’s press release:
Seattle Art Museum and Seattle Asian Art Museum will be open and free from 10 am to 5 pm on Wednesday, May 18. Additionally, Seattle Art Museum Downtown will offer free tours of the special exhibition, Nick Cave: Meet Me at the Center of the Earth at 1 and 2 pm.