There are many restrictions in both countries. First study the general European drone rules here:
Drones & Air Mobility | EASA. There are 3 open categories of flight
A1,
A2 and
A3 with different restrictions depending on the class of a drone: C0 – max 250g, C1 – max 900g etc. and level of your drone operator/pilot license. You can find the details here:
Open Category - Low Risk - Civil Drones | EASA
If you are a non-EU visitor read the requirements here:
I am a non-EU visitor / drone operator ‘open’ category | EASA.
You will have to register as a drone operator in the first European country you are going to fly and pass an online test – easy and fast for
A1 and
A3 category, more advanced for
A2 category of flight.
Apart of European rules, there can be additional restrictions in particular countries. Check also here:
AUSTRIA:
dronespace.at die Austro Control Drohnenplattform - EN
GERMANY:
Drone Laws in Germany | UAV Coach (2023)
In both countries there are many no-drone zones or restricted zones, especially in towns and over or close to popular places like castle. You can download applications which tell you restrictions in the place you are.
German: DRONIQ -
Droniq App - Drone App "Where can I fly my drone?"
Austrian: AustroControl -
dronespace.at die Austro Control Drohnenplattform - Austro Control Dronespace
Though I live in Poland and I have high, even BVLOS European drone operator and pilot license, especially flying in Germany and Austria is a real nuisance. Even if I know my rights, the police or guards usually don’t know the complicated drone laws and rarely speak English.
So even if I check the place is legal for my flight, I do everything to avoid anybody. I start from a place where I can’t be seen, make photos and videos as quickly as possible and disappear. And in case of e.g castles, I chose the time where the place is closed, and most people sleep, usually at 5-6 AM. Also the sunrise light is wonderful then. But you can do it only in summer. In December it will be impossible. And I usually look for the correct place to start my drone a day before with my car. If you travel by train, you will be less mobile, and you will probably be mainly in no-fly or restricted zones.
It’s my experience. I hope helpful for your decision to fly or not to fly in Germany and Austria.
BTW, in e.g. Poland, England or Italy it’s much easier to fly drones legally with much less problems.