In the "Mathcamp standard week" at the residential version of Mathcamp, we teach classes Tuesday through Saturday, so the Mathcamp "weekend" is Sunday and Monday. During the weekends throughout camp, the staff (and campers!) organize lots of different field trips. Sundays are for relaxation and small-group outings; major field trips are scheduled for Mondays, to avoid the crowds. All field trips are optional; some campers just stay on campus and take a break (or work on math).
A few examples of field trips we've run in the past few years: