Eli and Edythe Broad built this museum in 2015 to house their 2,000-work collection and, unusually, to keep lending it out. Diller Scofidio + Renfro designed it as a "veil and vault": the porous white honeycomb shell filters daylight into the galleries while the concrete storage vault sits visibly in the middle of the building, with viewing windows into collection storage. Admission is free. The stair escalator tunnels straight through the vault so you pass the storage on the way up.
Source: The Broad, official museum history and collection information; The Broad, official architecture documentation; The Broad, official visitor information