It's a part of Wittenbach (in German "Ortsteil").
You can check it here:
- https://de.wikipedia.org/wiki/Wittenbach_SG
- https://search.toponymes.ch/de/record/4041461/
- https://www.wittenbach.ch/suchen?query=Kronb%C3%BChl&selectedTab=website&selectedTabOrder=&selectedTabFilter={}