It may be a former prison whose name means fortress, but you can’t feel more carefree than when seated under a parasol on Festningen's sheltered terrace looking out over the water to Aker Brygge; the period building is charming too though, with a smart yet cosy feel, and the team will welcome you warmly wherever you sit. The terrace menu comprises brasserie classics such as burgers and moules frites, while the modern restaurant menu offers unfussy, attractively presented dishes like hamachi crudo with marinated cucumber, yuzu vinaigrette and horseradish or grilled chicken supreme with rosemary oil and spinach.