There you go. Ethymologically, one of the theories about the word "viking" is that it has its roots in that they came from a "vik" (="bay" in Norwegian) - ie the area now known as the Oslofjord, which is where many of the important historical relics from this period have been found.
And thanks for backing me up on Bergen!
W.
Spending a day seeing sights including Vikingskipsmuseet (Viking Ship Museum) in Oslo is okay, but then I'd get out of the Oslo area and go west and north quick-fast as the western part of Norway is far more interesting if history, nature and wildlife is your cup of tea. I would certainly not pick Vestfold over Bergen!
Bryggen is admittedly a bit hyped, but Håkonshallen, Edvard Grieg's amazingly well-preserved home at Troldhaugen and the view from Fløyen in a cozy almost South European atmosphere (hopefully helped by passable weather...) make it all worth the while. A extra tip is going to the history of Natural History Museum to behold their jaw-dropping exhibit of a mounted blue whale skeleton in full size.
For fjords, if you're in a hurry, Sognefjorden and Geirangerfjorden are safe bets and relatively easily combined with stave church visits at Urnes and Borgund for history. A hidden jewel is the mountain road from Hellesylt by Geirangerfjorden to Leknes in Hjørundfjorden - perhaps the most dramatic road in Norway. Get a ride or hire a car if possible.
Break the bank to stay at Union Hotel Øye - kaiser Wilhelm II's favourite during his numerous stay in Norwegian fjords - and then catch jugend architecture at Ålesund and penguin feeding at the city's aquarium. Wild life is covered by visiting the amazing bird nesting mountain at Runde - again, an underrated gem.
If you do go North, I think Helgelandskysten is your best bet - and by plane. Nice scenery, not that far north (in terms of travelling time) and you can have midnight sun. But it's a part of Norway best enjoyed by a two- or three-day drive, or even better boat cruise...
Thanks guys for all your great tips. I've had some unfortunate things happen which mean I will have to delay myNorway plans. However, I have read & will keep all your great ideas. They will inspire me to get there as soon as I can. And hopefully others will find this thread really useful too.