A couple of years ago, I led a summer camp for middle schoolers called the "Pearson Young Scientists" at the California Academy of Sciences. It was a super fun program to develop and facilitate, taking a group of a dozen middle schoolers from the Bay Area and exposing them to citizen science, local parks, and game design.
I personally learned a lot from this program, including how beautiful and important the Mount Tam Municipal Water District is to the region, how to create geo-located digital games using the platform ARIS, and how to keep engaged and excited a diverse group of middle schoolers for two weeks during the summer.
Here's a neat video about the program created by the Pearson Foundation.