Penn Books at 36th&Walnut. The book store shares the ground floor with a coffee shop and a few other uses. The upper floors are a hotel.
These photos show, from different angles, the public space used for cafe tables.
Just to the right of the camera in the photo on the left are the stairs to the subway/surface cars. Trolley lines 11,13,34,and 36 go under ground at 40th Street and share a tunnel that takes them under the heart of the Penn Campus to 13th&Market downtown.