Boston in a day?

If you want to distill Boston into a single day, I'd plan a few walks.  

One through Beacon Hill, to the Public Garden, and then down Newbury St, walking one block off Newbury to go through Copley Square.

Then I might head over to Harvard Square to wander through Harvard Yard and see the University. Plenty to do and eat there.

The Seaport District is Boston's latest and trendiest neighborhood, and it's a nice walk from there to the Waterfront and New England Aquarium.

Feel free to reach out if you need a specific recommendation!

Not sure how long you have or where you will be, but the North End is a great area to explore if you only have a day. Great Italian food AND history! You can walk any part of the Freedom Trail including a shopping/eating stop at Faneuil Hall and historical stops at Old North Church, Old State House, and Paul Revere House.  If you're not into history, you could take a stroll down Newbury St to Boston Common for a taste of Boston shopping with old brick charm. Lastly Boston Duck Tours are a fun way to see the city from land and water! 

The answer all depends on your interests.

If you're a foodie: Faneuil Hall is a mecca for food. I've tried so many things and there and it's all so good. You'll have a hard time narrowing down what to get... and finding a place to sit. Be ready to make friends and share. For dessert, walk on over to North End. The two best pastry shops (based on 25+ years of taste tasting experience) are Mike's Pastry and Modern Pastry. I highly recommend cannoli's and pizzelle from either! For dinner, Boston has everything from pubs to classy restaurants and everything in between. Just for the novelty, I've always enjoyed Top of the Hub. The view is hard to beat and the food is amazing!

If you're an art lover: You won't be disappointed by the Museum of Fine Arts at all, but I've always found the Institute of Contemporary Art to be incredibly fascinating as well. It can also be very lovely to walk down Newbury St and check out the many galleries.

If learning is your thing: I'm a total nerd, so I have spent far more time than most have at the New England Aquarium and Museum of Science. If you have kids in tow, these stops are even better!

Enjoy!