As far as big public projects go, the Salesforce Transit Center exerts a kind of unmistakable presence in downtown San Francisco. It’s huge—spanning nearly four blocks. And it’s meant to connect the greater Bay Area to the city through a network of regional transit lines.
There’s a 5 acre park perched on top, and on ground level, you can find food and shops operating out of the terminal’s retail spaces.
What most people who visit don’t know is that beneath the streets and sidewalks are empty, cavernous spaces that stretch the length of the transit center above.
This is the Trainbox, the space built out and reserved for the rail lines that MAY someday connect downtown.
https://www.kalw.org/2025-06-16/san-franciscos-ready-made-future-train-portal