4-year high school
A lot of non-Americans think it’s pretty weird that High school only lasts 4 years. In England, the equivalent: a secondary school, lasts for 5 years, with 2 years of college added afterward. In that context 4 years doesn’t sound like long at all.
But this is because our middle school includes some of the years they would spend at secondary school. High school is just the end bit, really. Dividing into 3 different schools means that you can have more specialized facilities in each one, so it works out much better for us.