The narrow path had opened suddenly onto the edge of a great black lake. Perched atop a high mountain on the other side, its windows sparkling in the starry sky, was a vast castle...
While it's a great place for Hogwarts students to hang out on a warm spring or summer day, or ice-skating in the winter, the first years cross this monstrous body of water every year to get the full impact of seeing Hogwarts castle.