I think since 109 prospect is over the tracks it's not at all Union Sq but Inman Sq. Though technically since it's Somerville it could be "Portuguese Plaza".It absolutely is. I remember when it first went on the market, I watched a person in a Tesla try and take the turn for a good 5 minutes, give up and then just block the driveway.
They've since gone in and tried to expand the garage door... it was a hackjob and it looks like it.