Gesamtschule Unterstrass is a private day school at Seminarstrasse in the Unterstrass district of Zurich, founded in 1981 by Daniel Lienhard and by Christine and Dieter Rüttimann. It teaches children from the age of four to sixteen across four mixed-age stages — Grundstufe, Unterstufe, Mittelstufe and Oberstufe — with just under a hundred pupils in total. The Grundstufe brings kindergarten children and first-graders together and is normally completed in three years, though it can be done in two or four. Each stage is led by two teachers working together, and lessons are problem-based, practical and enquiry-led. Teaching is in German. The school shares a campus with Institut und Gymnasium Unterstrass, which are separate institutions, and acts as the partner and laboratory school of the Institut. It received the Klaus J. Jacobs Best Practice Prize in 2015.