Hogwarts Castle

From the Harry Potter Wiki:

Hogwarts Castle is a large, seven-storey high building supported by magic, with a hundred and forty two staircases throughout its many towers and turrets and very deep dungeons. The castle was built in the late Early Middle Ages (c. 993) by a wizard architect and the four most celebrated wizards of the age: Godric Gryffindor, Helga Hufflepuff, Rowena Ravenclaw and Salazar Slytherin. The castle houses Hogwarts School of Witchcraft and Wizardry, regarded as the finest wizarding school in the world.

At Absit Omen

Some changes have occurred to the castle and grounds since 2008.

Hospital Hut and Hospital Wing

On September 3, 2008, the Hospital Wing at Hogwarts School was so damaged that it was closed off. The damage was caused by Fiendfyre mistakenly cast by student Darcy Bloxham (see Darcy's Fire). Because of the Dark Magic, the hall has been as yet unsalvageable. The doors were sealed and was no longer in use. Inside were the charred remains of the room, the walls completely blackened, and support beams, windows and furniture all completely destroyed.

Shortly following, Head Healer Tulojow Nagde operated out of the new Hospital Hut. The Hospital Hut was a much more modern facility than the old Infirmary, with private living quarters, multiple private recovery rooms and a warm scenic environment.

As part of the refurbishment efforts for the '09-'10 TetraWizard Tournament, most but not all of the Hospital Wing was rebuilt, with the unfixable sections walled off. It was reinstated as the primary hospital for the school. Some signs of the Fiendfyre damage are still seen around the entrance.

In 2011, Headmaster Knox Greyfriar designated the hospital hut's living quarters as guest housing, and the other rooms for storage. It remains locked but students still occasionally find their way in...

Hagrid's Hut

In 2011, gamekeeper Sylvain Onuris added a human-sized annex to the giant-sized hut.