The new Oslo National Museum is the latest mega project to open along the Norwegian capital’s increasingly buzzing waterfront in the past couple of years. However, unlike its most recent predecessor, the kookily slanted-at-the-top Munch museum, its arrival and presence is more muted. And this despite its whopping 54,600 sq m size and impressive £510m price tag. Composed of a low-slung structure that gets taller as it moves away from the harbour in line with the surrounding streetscape, it is topped by a translucent volume to the fore and a darker volume behind it. At the front it joins up with two existing 19th-century former railway buildings (one of which is now the Nobel Peace Prize museum), forming a new piazza that leads to the entrance foyer. It is at once a monumental and encyclopaedic museum for the 21st century, bringing together the collections of five existing city institutions dedicated to art, architecture and design – yet it is somehow also modest and minimal.