When we planned the trip, we weren't sure whether we would have either the time or the inclination to go as far as Trondheim, before turning the car south again towards Oslo. But the weather was good and it only added a few hours to the day. We found lunch on the street downtown and spent two hours walking around the cathedral and Old Town.
Trondheim's Old Town is down towards the river, east of the newer part of the city. The Old Town Bridge (Gamle Bybro or Lykken's Gate) across the Nidelva River dates to 1681, although it's been remodeled and refurbished quite a bit since then. It also doesn't open any more, which is a shame, since it would have been neat to see the old hardware in action.
The river itself is lined with the old warehouse buildings, looking a little like the old wharf areas in Copenhagen and Bergen.
Trondheim was the farthest north we got on this trip, or that either of us had ever been before, not counting airplanes flying over Baffin Island and our brief stop in Reykjavik on the way home (although it is only a tad farther north than Trondheim). For reference, Denali and Kristiansund are both 63.1°N, but Trondheim is 63.4°N. Reykjavik is 64.1°N.
It was wonderful seeing everyone out enjoying the beautiful sunny weather - and realizing just how far north (and how lucky) we were.