The staircase to the original exit and down to the orange line
#0730 is the back of a Wonderland train loading up rush hour commuters
The opening in the bricks of the Old State House that is the original Blue Line entrance
The fare gates in the narrow Old State House fare control area.
Heading down the staircase to the Bowdoin Blue Line and Oak Grove Orange Line platforms (although which staircase matters less for the much deeper and more complex Orange Line platforms)
Orange Line for Oak Grove, or Blue Line for Bowdoin on an intermediate landing