From the South Take best route to Boston via I-93/Southeast Expressway North. Continue on the highway as as you enter the tunnel. In the tunnel, take the Government Center exit (exit # 23). On the ramp, proceed to the left most lane and take your first left toward Fanueil Hall.  Continue around the bend and take your first right, which brings you next to Fanueil Hall. Follow the road to the end and take a right.  Take a left at the second traffic light (New Chardon Street).  Go to the top of the hill and take a left at the light (Cambridge Street).  The Center Plaza Building will be on your right after your first set of lights.