A thousand years
Fifth year students at Hogwarts are fifteen years old. Most students will turn sixteen throughout the school year.
11
16
He was 11 when he went to Hogwarts
11
15
11
14 Years Old
Hogwarts itself wasn't attacked, but the people inside it were. The final battle between Harry and Voldemort took place at Hogwarts leaving much of the castle damaged.
Teddy Lupin was born in 1997. Nineteen years later, he is 19 years old. Students leave Hogwarts at 17. Therefore he is too old to be at Hogwarts, but his character was never said to be getting on the train. He was at King's Cross to say goodbye to Victoire Weasley.
No. First years at Hogwarts are 11-12 years old and seventh years are 17-18. Hogwarts includes high school aged students, but is not exclusively a high school.
Hogwarts students are given tickets to the train for free.As Hogwarts is fictional, nobody could visit it in real life.