Think about it...Your great grandpa who lived centuries ago and who is still known for the great inventions that he made in the past wrote you a letter!Ibn Sina the sultan of doctorsKatip Chelebi the important historian and geographerSinan the great architectRumi the famous poet and authorPiri Reis the first navigator who drew a world map andYunus Emre the poet who captured everyone's hearts with his poems wrote you a very special letter. It is very exciting isn't it?When you read these letters you will both travel to the timesyour grandpas lived in and learn about their wonderful works.Come on kids! Now it is time to read the letters from our "Wise Grandpas"...