Security

The school is protected by much more than walls, whenever Muggles come near it, they see a crumbling ruin with a sign saying 'Danger, do not enter, unsafe'. Muggle electrical equipment, such as electronic bugs or radios, etc, do not work around the school as there is so much magic in the air. It is impossible to Apparate or Disapparate inside the grounds. There have even been Dementors stationed at the gates when Sirius Black was on the loose near the place (although the headmaster, Albus Dumbledore was not entirely pleased with this arrangement).

The students are not allowed to enter the forbidden forest, as there are many dangerous creatures living there, nor are they allowed to go to the town of Hogsmeade before 3rd Year, and only then on selected days.