Transport
Hogwarts carriages
The Hogwarts carriages take students who are not first years from Hogsmeade Station up to the castle. They look self-moving until the passenger can see the thestrals in the harness. Harry rides them for years before he can see what pulls them.
In the books
Harry Potter and the Order of the PhoenixChapter: Luna Lovegood
Harry sees the thestrals pulling the carriages he has already ridden in earlier years. The first visible team is in this chapter.