I'm a person who highly values a nice relaxing weekend at home with my husband, and there's hardly anything i would give that up for. Still don't know why we decided to go out on Saturday to a new place, it had to be close enough for a day trip and have just enough to see in one day without rushing. Living in Oslo at the time Fredrikstad was a natural choice, and i personally didn't even know what to expect.
I was quite positively surprised by the landscape design of the old town, turns out this city used to be a capital of some sort, it's got a few old castles around, still got it's old city wall and a monument of king Fredrik, after whom the city was named.
It's a nice place to just go around, walk the old town, enjoy the old architecture, then wander into the new part of the city for a reality hit coming out of some kind of fairytale place.
I enjoyed my day there although it started raining on us by the end of it, but that's when we got into this good looking Mexican restaurant, had nachos and stuff then headed home.
I liked it, it's worth a visit. And if it's summer, maybe you should also get to Hvaler, a group of little islands right outside Fredrikstad on the fjord ... a very popular summer spot for the Norwegians :) Enjoy!