I did Europe on $5 a Day back in 1969 after a year of study in Aix. I seem to remember waiting for tours to be held in the various languages for chateaux or German castles. It appears that nowadays you rent an audioguide or just walk around and read the signs in English. Am I right?
Well, yes, things have changed in 40 years, but some things remain about the same. Sometimes the best option is still a tour in English. And there's also Rick's and other books. Where Rick gives a tour in a chapter of a book they're detailed, and now he's putting some of them into audioguide format you can access with an MP3 player. But sometimes there are not signs in English, even these days.