The New Museum’s extension, which opened in March, is quite literally a breath of fresh air. The institution’s two-decade-old building, by the Japanese firm SANAA, was always beguiling from the street—it still looks like a stack of presents, ready to be opened. But until now it was fatally cramped inside, each floor besieged by its own circulation space. The new addition fits onto this existing structure like a giant prosthetic. The principal architect, OMA’s Shohei Shigematsu, has compared it to the launchpad armature for an orbital rocket. In addition to a generously proportioned atrium and stairway, which provide access to each gallery floor, the building now has much-needed amenities including a larger gift shop and that must-have for any contemporary museum: a nice restaurant. It’s called Oberon, and its doors open this month.