The David Chipperfield-designed extension to Museum Folkwang in Germany will be unveiled in Essen on 28 January.
The 26,360m² scheme has been extended with the addition of six new wings arrayed around a series of courtyards.
New exhibition spaces including a cafe, restaurant, bookshop and library have been added to the museum.
The Museum Folkwang is the longest-established museum of contemporary art in Europe.