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- Oetenbach Priory (Kloster Oetenbach) (dissolved), Oetenbach (Zürich): Domincan nuns (c.1284-1525)
- Olsberg Abbey (Stift Olsberg) (dissolved) at Olsberg (Aargau): Cistercian nuns
- Oujon Charterhouse (dissolved) at Arzier (Vaud): Carthusians
Read more about this topic: List Of Christian Religious Houses In Switzerland