Go to at least one May Ball. If you can, go to one of the two most lavish (Trinity or St. John’s). I’m no fan of pomp and circumstance or throwing down a couple hundred pounds on a party, but there is nothing quite like enjoying an all-night festival of fireworks, food, music, punting, and games, all with many good friends and in the spectacular setting of a Cambridge college courtyard. If you truly can’t afford it, volunteer to work during one of them, as volunteers often get free (or at least reduced) tickets (watch your email for the call for applications).
Go to several garden parties. Almost every club or other organized body of students will hold one. Some are free, others cost money, but the distinctly British tradition is good fun. Especially if it’s not raining.
If your department offers it, consider supervising undergraduates. It can be a fun way to get a glimpse into the undergraduate educational experience at Cambridge, practice teaching, meet some undergrads, and make some extra money. The pay is quite good (and even better for larger groups of students) but beware that you will get a separate check from each college to which the students belong.
Go to Edinburgh. With its beautiful architecture and green spaces, many excellent cafes and restaurants, and rich history, it has something for everyone. Moreover, it’s just a train ride away from Cambridge and the tickets are quite reasonable (£30?) if purchased in advance.
If you enjoy hiking, go to Snowdonia in Wales, the Lake District in England, and anything in Scotland, particularly in the early fall or late spring/summer. Be prepared for awful weather… and be thankful if it doesn’t arrive.
Take visiting friends to formal dinners, especially at one of the nicer (sorry, Churchill) dining halls (e.g. Trinity). Most find it a very unique and memorable experience.
This post is adapted from a final report I submitted to the Churchill Foundation - the sponsor whose generosity is allowing me to spend one year at the University of Cambridge. It was written in September 2012.