Kalkalpen national park is huge, and if you wanted to you could spend days hiking it all. If you like to climb peaks, Hoher Nock is a good one. The closest train station or Bahnhof is Rossleithen, which you can reach from Salzburg or Linz easily. Facing the mountain, cross the train track and turn left towards Rading, follow the road to the end & turn right on a road to take you to the Kalkalpen park entrance, then a carpark to hike to the top is not far from there. I saw 10 or 15 cars park there when I arrived. It's probably 4 or 5km to walk from the train station, so if you didn't want to walk it you could hire a bike from Salzburg or Linz or find a taxi company somehow, the local buses only run 2 or 3 times a day. You could link this up with the Alpine Coaster at Windischgarsten station nearby, or Dr Vogelgesang Klamm waterfall at nearby Spital Am Pyhrn station. Windischgarten is a nice town if you were looking for a hotel and some restaurants.

The scenery is amazing. The lynx population is growing steady and is taken care of. Wide long hills of quiet and tranquility. Very enjoyable for hiking, cycling and climbing.