Fillory - The Wizards

In the secret world of hidden knowledge, power has a terribly high price
Quentin Coldwater is about to graduate from high school. School bores him like everything else except Fillory, the magic land of the fantastic books he loves. But suddenly Quentin, who was just walking through Brooklyn, finds himself in a magical world, at a secret magic school: Brakebills College. And also Fillory really exists. But it is not an ideal world, but a dark place from which a terrible threat emanates. Quentin and his friends embark on a dangerous journey and have to face a decisive battle
"Fillory to Harry Potter is like a glass of whiskey to a cup of thin tea. Firmly rooted in the tradition of both fantasy novels and general literature, he alludes to the worlds of Oz and Narnia - Harry Potter also sends his regards. But don't think of it as a children's book. Grossman's emotional worlds are thoroughly mature, his narrative style dark, dangerous and full of surprising twists and turns. Hogwarts was never like this"
George R. R. Martin, The Song of Ice and Fire A Game of Thrones