What are the entrances to Hogwarts?

Answer 1

In the girls bathroom where moaning Myrtle used to live and it was entered by speaking parseltongue beside a tap encrypted with a small snake which has never worked. The sink then moved aside and allowed you to jump down a passage.

Answer 2

The three passages in and out of Hogwarts that were described in the books were: the one from the Whomping Willow to the Shrieking Shack; the one behind the mirror on the fourth floor, which was caved in; and the one through the one-eyed witch's statue that led to Honedukes. The other four were not described by Fred and George because Filch, the caretaker, knew about them.

Answer 3

The seven secret passages at Hogwarts:

A passage beneath the one-eyed witch statue by the stairs to the DADA classroom, leading to the cellar of Honeydukes. A passage behind a mirror on the fourth floor, caved in as of 1993, leads to somewhere in Hogsmeade. A passage beneath the Whomping Willow, leading to the Shrieking Shack. A passage behind the statue of Gregory the Smarmy. Three unspecified passages, said to be known to Argus Filch.

Answer 4

The only official entrance to Hogwarts is through the entrance hall. The rest are secret passages. One of these is through the Room of Requirement, one from Honeydukes cellar and one through the Shrieking Shack. The rest are blocked.