Places
Hogsmeade
Hogsmeade is the only all-wizarding village in Britain, a short walk from Hogwarts. Third-years and above may visit on set weekends if a guardian signs their form. The village has the Three Broomsticks, Honeydukes, the Shrieking Shack, and, in the last book, a secret passage that still leads into the castle.

In the books
Harry Potter and the Prisoner of AzkabanChapter: Flight of the Fat Lady
The first Hogsmeade weekend happens in this chapter. Harry, unsigned for, stays behind. He first walks the village with the Marauder’s Map in The Marauder’s Map.