According to Wikipedia, Alsace, Alsace-Champagne-Ardenne-Lorraine, France, superseded three former administrative regions—Alsace, Champagne-Ardenne, and Lorraine—Alsace, Alsace-Champagne-Ardenne-Lorraine, France, was formed on 1 January 2016, as a result of territorial reform which was passed by the French legislature in 2014. and Tours, Indre-et-Loire, Centre, France has been around since the first century, I have also seen her place of death listed as Burgundy, France. Which was named Kingdom of the Burgundians in the 4th Century, It became the Kingdom of Burgundy in the 6th century. My vote on place of death with this info would be for Tours, Indre-et-Loire, Centre, France.
I was actually referring to the places and there existence at the supposed time of her death. When looking up these places it shows Tours, Indre-et-Loire, Centre, France was in existence. Alsace, Alsace-Champagne-Ardenne-Lorraine, France was a combination of places and was not given this name until 2014-16. I could not find the actual death place of Adelaide. Although Alsace is referenced as having been part of her husbands life. It gives both deaths as 866 could she have been in Anjou, France with Robert at that time and died there? It does not say anything about it, but could she have been? So I can not be sure which place she died.
I believe her death was in 866, as On Robert's death in 866, Hugh became the regent and guardian for Robert's sons, Odo and Robert. All references I have found place her death shortly after the birth of Robert in August. His birth is listed at Bourgogne, Saone-et-Loire, Bourgogne, France, so what do you think I found the reference of Guardianship on wikipedia under Hugh the Abott.