And I don't know... What about the Louvre, Mélusine?
Do you know how much I would LOVE to spend a night "alone" (With less, less, less visitors.) in the Louvre ? *Can't understand they hadn't think to offer that, even if it had to be more expensive*
Sunflower is right : I
might have forget the minor problem of trolls.
(An island ? Gunkanjima ? But the architecture is less... more...)