The primary mode of transportation to Hogwarts is the Hogwarts Express that students take at the start of each school year. Students board the train from Platform 9¾ at King's Cross station in London. The train leaves at 11:00 am and arrives at Hogsmeade Station, near Hogwarts, some time after nightfall.
Harry: How do we get to the Hogwarts Express?
Ron: You have to go through Platform 9 and 3/4.