"You can't Apparate inside the Hogwarts grounds, how often do I have to tell you?"
-- Hermione Granger
Hogwarts castle is located atop a cliff overlooking a lake. The lake is to the south of the castle (PA6) and the front doors face north (see commentary below). There is a small underground inlet, it’s entrance covered with hanging ivy, that leads to a stony beach below the castle at the base of the cliff. From here, a path leads up to the front door of the castle. A road runs around the lake, past the village of Hogsmeade, to the south of the lake where the railway station is located. The grounds are quite extensive, taking in a large forest and enough open space that folks in the castle never notice the fiery breath and roaring of group of four angry dragons kept in a paddock near the forest for the Triwizard Tournament. A wall or fence encloses the entire area. The main entrance gate is flanked by pillars on which stand statues of winged boars.
The Quidditch Pitch is to the west of the castle and the Forbidden Forest is to the east. Hagrid’s hut is an the edge of the forest (PS8). The pumpkin patch and vegetable patch are behind it (CS7, PA16, PA21). There is a wide flat lawn opposite the castle from the forest and Hagrid’s hut where the first-years took their first flying lesson. Sloping lawns lead down toward the forest and border the lake. Near the lake the white tomb of Albus Dumbledore.
The entire grounds as well as the castle are protected by magic spells. Hogwarts is hidden from Muggle eyes. The castle is bewitched so that if a Muggle looks at it, all they see is a moldering old ruin with a sign over the entrance saying DANGER, DO NOT ENTER, UNSAFE.
The castle main doors face north, as shown on Rowling's map of the grounds seen in the "History of Magic" exhibit at the British Library. Previous maps from Rowling had not included the directions, so while those older maps agree in the arrangement of the various features, they donot say which way things faced.
Until recently, the best canon evidence suggested that the doors faced west, based on this sentence in book three:
"He was standing next to Hermione in the deserted entrance hall and a stream of golden sunlight was falling across the paved floor from the open front doors" (PA21).
However, this new version of Rowling's map includes a compass rose and clearly indicates that the doors face north. The new map does not create a canon error, however, since the sun sets in the northwest in June and the sunlight could easily be slanting in from the left into the entrance hall as Harry and Hermione walk toward the doors.