Last Updated: 7th Jun 2012
The trolley tour of Boston, offered as an optional, is the best way to see the entire city. Take it at your own pace, but I would suggest stopping off at the USS Constitution and Fenway.
I went on two tours alone...I made life-long friends along the way! That's the nature of Contiki.
Christmas Markets in Vienna are great. Buy some mulled wine (Gluhwein in German)which is served hot and is quite spicy. The mug it comes in is yours to keep - a great souvenir -but if you don't want it return it and get your €2 deposit back (Pfand).