Universities, with an abundance of professional educators, students, and meeting spaces, are perfectly positioned to offer enrichment to the K-12 community. Two examples that come to mind are the University of Colorado Boulder (CU) Wizards program: https://www.colorado.edu/cuwizards/ and The Rockefeller University Science Saturday: https://www.rockefeller.edu/science-saturday/
Both offer incredible learning opportunities to young learners by carefully crafting how to present complicated topics to this audience.
The Boulder Center for Interactive Learning at Dawson (BCILD) hopes to learn about, and share, information on other such opportunities within K-12 communities.
Photos taken at CU Wizards event Boulder, CO, Saturday 01/26/2019