Things to do in Cambridge

Hey guys this is super last minute, but my parents are in town and we decided to go into Cambridge for the day. Any suggestions on what to do/eat?? I've been before but just in passing not really done much while there. There seems to be a lot recommended on sites like trip advisor, so not really sure where to start. Any recommendations would be awesome!! thank you!

You've probably already left for the day...but

The central market is good for a stroll
Most Saturdays there's also a little crafts market down St. John's/Trinity street just past Heffers Bookstore
Down that little passage (All Saints) by the crafts market is a cool little charcuterie/cheese shop (Cambridge Cheese Company) which is really nice for nibbles.
Just around the corner is the Round Church....which was originally a Norman chapel....but with murky ties to the Knights Templar..

Thank you sonofasailor!!! We are just about to leave, so this is great.

To be honest you can pretty much burn a day wandering around...

Oh and if you are driving in and see the American War Cemetery, think about stopping....it is a very moving place...

To be honest you can pretty much burn a day wandering around...

Yes, we spent a whole day walking, did a punt tour which was nice. Had lunch in a nice pub. Think we're going to go back Monday instead of London.