While we were touring the northern Waldviertel (Forest District) of Lower Austria, we stopped off in Heidenreichstein to view the beautiful castle and have lunch in the village. We asked a few locals where they consider the best food was served close by and all directed us to the "Burgstüberl" opposite the castle. Thus, it is very well located for sightseeing. We enjoyed the 2 course daily special (Soup and Pork Chops with fries). It was very reasonably priced at € 6.90. It switches every day.
In July and August they are open everyday, but otherwise closed on Mondays.
The food is good basic "Hausmannskost" (every day home style cooking)
If in town, do as the locals and eat here.