Southern Pacific built the depot in 1935, and it was long known as Cahill Depot. Its architect, John H. Christie, gave it an Italian Renaissance Revival design: a three-story central waiting room flanked by two-story wings, faced in tapestry brick. It was refurbished in 1994, is on the National Register of Historic Places, and is named for former county supervisor Rod Diridon Sr.
Today it is the meeting point of the region’s trains: Caltrain, Amtrak’s Capitol Corridor and Coast Starlight, ACE and VTA light rail, plus buses to Santa Cruz and Monterey. BART service to a new underground station here is projected to begin in 2036.