(I'm a U.S. native speaker). I believe that all three sentences are, grammatically, perfectly correct. The sentence "Nowhere else in the world can you find more attractive scenery than in Switzerland" is, as a matter of style, more idiomatic and more natural than "Nowhere else in the world is found more attractive scenery than in Switzerland." The second sentence sounds awkward and formal, but I don't think it's incorrect. The third, "Nowhere else in the world has been found more attractive scenery than in Switzerland" is interesting because it's grammatically correct, but logically incorrect. It suggests a literal search, and a moment of discovery that was in the past and is now over. It would make sense to say "Nowhere else in the world has been found a better-preserved example of Hallstatt metalwork than in Switzerland." Notice that the meaning can be conveyed in a simpler way by saying "Switzerland has the most attractive scenery in the world." "Nowhere else in the world can you find more attractive scenery than in Switzerland" adds some shades of meaning. It puts the emphasis on Switzerland's uniqueness and superiority. It also gives the reader a sense of participation by using the word "you." In travel writing, journalism, and magazines, it is customary to adopt a slightly informal, colloquial tone, as if the writer were talking to the reader, and involving the reader by using "you" sounds friendly and engaging.

"Which one is the correct one that can be chosen to form the sentence?" It is the middle one, Noraaaah. Technically it should be: "Nowhere else in the world can one find such beautiful scenery as in Switzerland." However, in modern English pretty much everybody substitutes the word "you," for "one." "One," means a un-named person and is similar in meaning to "anyone." "You," is a personal pronoun and is used, in English, when talking directly to somebody else where the subject of the conversation is the person being spoken to: e.g. "Do you want some sushi?"

can you find