Legacy: This Town Aint Big Enough For The Both Of Us

I am in the most EU-ish bedroom in the EU. That is to say, I am lying in a refurbished room in the handsome 14th-century Chateau de Schengen, in the little village of Schengen, Luxembourg. From my casements, opened wide onto the sunny Saarland afternoon, I can see the exact stretch of the river Moselle