Columbia Play Project and Harper’s Playground are partnering to offer a free mobile children’s museum at Marshall Park, 1069 E. McLoughlin Blvd, Vancouver, for a day of fun and games for all ages, 10 a.m. to 3 p.m. Sept. 10. Grab your kids or grandkids and join a day of activities will focus on STREAM (science, technology, reading, engineering, art and math). Listen to the Vancouver Community Concert Band and enjoy a shave ice from Kona Ice. Learn more at columbiaplayproject.org.