Kastellet School is a heart zone school that offers a varied range of subjects, including a special department known as Regnbuen. The school emphasizes a safe and good school environment, and has health and welfare services available to students. In addition to the regular teaching offer, theme days and electives are organized for pupils from 5th to 10th grade, which provides opportunities for deepening and variety in learning.
The school also has an activity school (AKS) which offers free activities after school hours, and collaborates with Nordstrand cultural school to provide pupils with extra activities. Kastellet School emphasizes cooperation with parents and the local environment, which contributes to a holistic learning environment. Pedagogical profile is based on assessment for learning, which promotes students' development and learning process.