Do cultural improvements have to be worked to generate tourism?

[bbbt]

So with hotels, etc. culture from improvements (landmarks, chateaus, Moai, Japanese fishing boats, brazilwood camps, etc.) gets turned into tourism. Is this only for said improvements being worked by the city, or all improvements in the city radius?

 

[MKDELTA3]

They have to be worked as far as I know.

 

[Browd]

That is correct.