National Association of Math Circles Wiki
Math Festivals

Math Festivals provide one-time out-of-school opportunities for students to engage in mathematical exploration.

The following organizations have worked to create resources to host math festivals across the country:

Julia Robinson Math Festival, http://jrmf.org/

Gathering for Gardner, http://gathering4gardner.org/

The MSRI/ISA National Math Festival (Apr 2015) http://www.mathfest.org/