I'm currently planning 10 days trip to Sweden next month (I know it is not the best time of the year). I planned to stay in Stockholm for 5 days, but for other 5 days I'm still don't know which route to choose between go to Southeast at Kalmar to see southern Oland and Karlskrona or go to Southwest at Goteborg to see Tenumshede and Varburg Radio. Any advice please.

I haven't been to the South East, so can't compare the two, however I spent 2 days last summer going from Goteborg to Tanumshede and Varberg and really enjoyed it.

If you have your own car, then it is pretty simple to see all 3 of those in 2 days, as the E6 highway pretty much links them all. If really pushed you could see them all in a day. Without your own transport it may take a little longer as the Radio Station and Rock Carvings are a little way from the nearest station, so may require a taxi or a wait for the not so frequent buses.

Both the WHS are good, the Radio Station especially is impressive, and it is nice to see something of the town of Varberg too, you can even stay in the fort, if you don't mind being in a hostel.

If you do have your own transport then I can really recommend staying at HavRo. It is an organic farm just a short hop from Varberg, but with cabins that look straight out to the sea. It is exceptionally charming, very welcoming and has delicious food even by the very high standards of Swedish hotel breakfasts. (It may close for the winter though).

I guess you have your plans for Stockholm, but just to say aside from the WHS the Vasa museum is really worth a visit, as are the cool cafes and shops in Södermalm.

I was in Sweden for 12 days last summer, and managed to fit in all the Stockholm sites, plus Falun, Engelsberg, Visby, Öland, Karlskrona, Varberg and Tanum - everything by public transport. So timewise, there should be plenty of time to cover all sites. Kalmar is a very pretty town, and Öland is a really beautiful island, but only in summer - when you go there in March, everything will be still be covered deep in snow, and you would miss the qualities that make it a WHS. So I would probably opt for the western route and take in the radio station and the rock paintings.

Thanks you very much for all information especially farm stay from Meltwaterfalls :), the big problem is that March is not an ideal time to visit Sweden at all as most of the places are still close and full with snow. I will try to visit Tanum and Karlskrona which can be visit in Winter, but I also look for Denmark as a substitute plan, the weather should be better there.

Glad it was of some use. Winter may not be the best time but it does look very nice with snow everywhere.
I just flew over Oland this afternoon, and there was a lot of snow so maybe not the best time to visit, but who knows.

I would like to report my freezing Sweden trip, it turned out that snow and winter really unwise to visit Kalmer and Goteborg so my friend took me to Lappland instead, it was a great trip to see Aurora Borelis and Ice Hotel. However at the end I only saw 2 WHS on this trip the Laponian and Drottningholm Palace! Thanks again for all your recommendation from meltwaterfalls and evilweevil, I'm sure it will be useful next year when I go to Sweden again in better Summer.