The castle which you can see not far from the resert city Bad Fussing (and a little far from the city Passau) - it is a castle Schloss Ortenburg. The castle is not very big, with a little museum and a restaurant in the basement (it is closed for repairs until May 2020). According to reviews, you can stay in this castle for a while - there is a small hotel. From Bad Reichenhall this castle is situated rather far, and the shorter road goes through Austrian autobahns. So be careful and don't forget about the vignette.
The address of the castle: Vorderschloß 1, 94496 Ortenburg, Germany
The museum of the castle works from April to October, Monday is a weekend day. The working time is from 10 until 17 o'clock. The cost of the adult ticket is 3,50 euros, children and teenagers under 18 - 2,00 euros.
In June the Knights tournaments near the castle are held - Ortenburger Ritter Spiele. 2020 the tournament must have been held from 11 to 14 June, it is difficult to say what will be then. Maybe everything will calm down and the illness will go away, the quarantine will be lifted and the descendants of ancient warriors will be able to meet again in a clearing near the castle. The website of the tournament is the least successful that i have seen. There's little information, the automatic browser translator denies to translate the text in Russian, and it is impossible to copy the text to translate it online.
As i understood you can buy tickets both for the whole festival and for its separate event. The entrance is 6 euros for children, 10 euros for adults. The full season ticket for 4 days for children - 17,00 euros, for adults - 30,00 euros. As usual there's a cultural program, a fair and a fire show.
Actually this place is rather interesting , there are lots of attraction nearby, that are not in my guide, this one and two other big cities - Passau and Linz. The first one is very interesting, because it was built at the place of confluence of three rivers, these are few small zoos, to the Bavarian forest from here is about 40 minutes by road, the road is glass... It is better to tell you the local guides, and maybe I will have something in time, but for now.