That's an epic example of brutalist architecture. It's a heroic display of dominance, permanence, and futuristic enthusiasm.
It's meant to show off what construction technology could do with concrete by turning it's back on traditional forms and preconceptions of what architecture could be. It was unapologetic and honest by exposing the raw structure as the finished material. It was also a way to explore how shapes, light, shadow, and space could be sculpted in ways that couldn't be done before.
For as ugly as it seems, there really are some cool things going on that I've grown to appreciate with this one. Where it sits in the middle of historic Boston is still very unsettling, as is they way that it treats the vehicle. There are always a jumble of cars parked right outside with no way of dealing with them that is organized or even looks good.