Construction is on track at the San Francisco Museum of Modern Art (SFMOMA), where workers put the last steel beam in place on the massive expansion Wednesday, writes ABC‘s local San Francisco affiliate. The building, designed by architecture firm Snøhetta, is being erected behind the institution’s current home, the work of Mario Botta.

SFMOMA has been closed for construction since June of 2013. The old building had seen roughly 11.5 million visitors cross its threshold since opening in SOMA (short for South of Market) in 1995, and was ill-equipped to accommodate the museum’s growing popularity and collection.