Boarding schools
Boarding school lot types would be so much fun! Like child and teen sims can stay at schools and have dorms, school grounds, and even have riding, outdoor painting, and woodwork lessons. Maybe set in a world like Henford on Bageley, or granite falls, with forests and hills around where sims can go trekking, picnics, or school camps. There might be two schools on different ends of the map, and some village squares where sims can go on weekends, like with permission slips. On vacations they can go back to their parents. Also number of sims should be increased in these schools, than average high schools.
School games between rival schools, fests, annual days, and many more celebrations and competitions can be held! It also be really cool if sims could form chat groups with friends, and a particular group of sims could always stick together and not drift off.