We would like to go to the National Park but on our own, we've searching in some websites and it all said that we had to book a tour to do a hiking experience. Could it be possible to do it on our own without any guide?
If you just want to do a day hike, simply park (cost a couple Euros and you save money if your hotel has a pass card) and hike. Berchtesgaden National Park has a flyer that you can download in English as well as other languages so you know some of the hikes and distances as well as where there is parking. You can also pick up the map at their offices. Be sure to carry adequate food and water.
Get quick answers from National Park center staff and past visitors.