Which city should be our base for three nights as we wander Austria? Which Do Not Miss attractions should we see? Worthersee sounds delightful.

What are you interested in: cities, castles, nature, beaches? What do you want to do in Carinthia? In which season?
Will you travel by car or by public transport?
Klagenfurt/Celovec and Villach/Beljak are cities. Velden is a village.

Yes, it would help to know what do plan to do/see in the area. I'm a bit familiar with the area as I have visited family there.

Klagenfurt is a pleasant little city, I've enjoyed a few day-trips there. Velden is mainly a collection of hotels and resorts, I didn't feel there was anything really to do there, but would be fine as a base. We spent a few hours in Villach once, and I didn't really find it interesting at all.

We will be driving in May and enjoy nature, glorious vistas, unique local happenings, few cities and castles. so Have decided we must spend a couple nights in Portschach am Worthersee and regroup. Thanks for your help.

​​​​I have fond memories of Pörtschach, it's where my late grandfather lived. The last time I was there (2009) it felt like the town was past it's prime--I think it was a prime vacation spot in the past, but these days my relatives seem to vacation in Italy or elsewhere.

We spent a long weekend in Pörtschach am Wörthersee about five years ago; like elberko writes, we were not terribly enamored with the area (it seemed a little faded), but it made a useful base for us to day trip to Lake Bled and for visiting Tromeja. Gondolas can take you to the summit for spectacular views and the point where Austria, Italy, and Slovenia meet.

Portschach makes for a good base, we spent 2 nights in September, 2018 there when exploring the Worthersee area by car. With a car, it was easy to drive around the lake and also make stops at Villach, Velden and Klagenfurt for a few hours each.