It's hard to see the appeal of historic buildings just by studying from a textbook.
The charm of historic buildings can't be understood just by reading a textbook.
The charm of historic buildings can only be understood by seeing them firsthand.
「魅力」は色々ありますが、今回は「appeal」と「charm」の2つをオススメします。
「歴史的建造物」は「historic buildings」です。
① It's hard to see the appeal of historic buildings just by studying from a textbook. （教科書で勉強するだけじゃ歴史的建造物の魅力はわかりづらい）
② The charm of historic buildings can't be understood just by reading a textbook.（教科書を読むだけじゃ歴史的建造物の魅力はわからない）
③ The charm of historic buildings can only be understood by seeing them firsthand. （歴史的建造物の魅力は直接見ることでしかわからない）
アメリカ合衆国 
