International School of Switzerland in Uri
An international and Swiss boarding school in Altdorf, between the mountains and the lake. IB Diploma and Swiss Matura, Grades 6–12.
- 1927Founded as a Catholic school, the Mariannhiller Seminar
- 1939–45Survives the Second World War
- 2017Becomes the International School Altdorf (ISA)
- 2020Carries on through COVID-19
- 2026Becomes ISSU under new management
- 2027Centenary celebration