If you rode the Mount and didn't get off, try that. What I mean is take an early boat and go to Wolfeboro for the day or Alton. Wolfeboro has enough to do for the day and then you can catch the Mount back to the Weirs.
Kelerhaus make your own sundays are always good. Town Docks in Meredith has entertainment on some nights. Meredith is a great trip, take the Doris E over.
No matter what wherever you go there are always those little brochure racks that have all the area attractions in them. Close your eyes and pick one out of the rack.
Have fun.