The dungeons of Hogwarts Castle are located under Hogwarts School of Witchcraft and Wizardry, and it is colder there than in the main castle. The Potions classroom is located in the dungeons, as is the entrance to the Slytherin common room and dormitories.

Located directly under the Great Hall, down the staircase you'll come to the broad stone basement corridor, brightly lit and decorated with food-themed paintings. You can find the Hufflepuff Common Room and Dormatories here as well as the Kitchen.

The Ground Floor is the floor above the Dungeons/Basement and below the First floor. It contains a number of courtyards, halls and rooms.

Upon entering through the huge oak front doors of the castle, students find themselves in the vast Entrance Hall, which is dominated by a marble staircase leading up to the first floor. The giant hourglasses which mark the house points are located in the Entrance Hall.

To the right of the Great Hall is the: staff room, the caretaker’s office, and classrooms are also found on this floor, as is a courtyard where students sometimes congregate between classes. The oak front doors open out directly onto the Hogwarts grounds.

In addition to the boards below the first floor also has a Store Room, Girls' Lavatory (Moaning Myrtle's Bathroom), The Quad, Advanced Arithmancy Studies classroom, Classroom 1A, Classroom 1C, Classroom 1D, Classroom 1E, Detention Chamber, Duelling Classroom I, Duelling Classroom II, First-floor corridor, Passage of the Fouls, and the Rear Hall

The second-floor corridor is a passage on the second-floor of Hogwarts Castle, accessible from a staircase connected to the first-floor corridor, a staircase connected to the Herbology corridor, a staircase connected to the library corridor and the Hogwarts Turris Magnus staircase. Off of the staircase are several rooms,[5] including the office reserved for the Defence Against the Dark Arts teacher. The corridor is lined with bookcases with a small seating area and at one end of the corridor is a tetraptych of Helena Ravenclaw. There is also at least one suit of armour along the corridor. Halfway along the corridor is a tapestry concealing a narrow staircase leading to the ground-floor.

The Third Floor has the following locations in addition to the Clock Tower Entrance: one of the three main entrances of Hogwarts Castle. It consists of a large open space at the base of the Clock Tower with two stairwells going up towards the upper levels of the tower. Opposite the main entry there is a large window. The massive pendulum of the Clock swings over this entrance. The entrance can be sealed with a portcullis (which can be lowered and raised with the aid of a lever) and the massive double doors can be locked with numerous bolts.

Charms Cooridor, Classroom 3D, Gunhilda of Gorsemoor Corridor, and another Storeroom

In addition to the following sub board locations, there is a storage room, Bathroom, Balcony, hospital tower corridor, and study area (also part of the library) with a secret passageway hidden behind a bookshelf that leads to the Seventh-Floor corridor, just opposite a portrait of Sir Cadogan. The fourth-floor corridor is a passage located on the fourth-floor of Hogwarts Castle, accessible through the Study Area. The corridor allows access to a balcony[3] and, to travel between the West Tower and Gryffindor Tower, one must use this corridor.

The corridor begins in the Grand Staircase Tower at the fifth floor level. It goes around The Quad and passes the Prefects' bathroom. It leads to the Fifth Floor Hospital Tower Corridor and then to the fifth floor balcony of the Clock Tower. The corridor also spans off into other rooms, one of which is the Music Classroom, another is Wizard Art.

Other locations include: Boys' Restroom, Classroom 5B, Muggle Studies Showroom, Wizard Card Collecters' Club Room, hospital tower corridor, and one of the cursed vaults.

The Sixth Floor Corridor is one of the many corridors in Hogwarts Castle. It includes a professor's office and is very similar to the Seventh-floor corridor.

There is the East Wing: a large hall with a huge fireplace in the center of the room and some portraits hung on the walls. There are various suits of armour, which guard the room after the sun is down. The entrance is located on the Glanmore Peakes' Corridor.

A Boy's Lavatory and a disused bathroom.

The Room of Rewards: a secret room at Hogwarts that notes students' various achievements. It can be accessed via the portrait of Vindictus Viridian on the Grand Staircase. It is not to be confused with the Trophy Room.

Other locations on the sixth floor: Classroom 6A, Storeroom, Empty classroom on the sixth floor, Glanmore Peakes' Corridor, Writing Supplies Room, and West Tower battlements

The seventh-floor corridor is a passage on the seventh-floor of Hogwarts Castle, accessible via a staircase on the sixth-floor, leading to the Fat Lady's Corridor and the North Wing and encircling the Quad. A staircase leading to the dungeons exists on the seventh-floor, also allowing access to the sixth-floor corridor below. Opposite the Troll Tapestry is a blank stretch of wall between a window and a man-size vase, where the Room of Requirement exists.

The North Wing: This wing has hundreds of bookshelves lined along the walls and various tables and furniture placed around the room. It serves the Castle as a reading room and study hall. There are two entrances; one in the seventh floor corridor and the other by the Fat Lady's portrait.

Towers:

West Tower, Bell Towers, Lookout Tower, Central Tower, Quidditch Tower, Astronomy Tower, Hospital Tower, Octagon Tower, Herbology Tower, Shaw Tower, Old Bell Tower, South Tower, Dark Tower, North Tower, Founders' Tower, Clock Tower, Headmaster's Tower, Ravenclaw Tower, East Towers, Greenhouse Tower, Gryffindor Tower, Beard Towers, Rotating Tower, etc

There are a lot of towers.