Gryffindor Common Room

The Gryffindor Common Room is located at one of the three highest towers the "Gryffindor Tower". The common room was hidden by the Fat Lady. The only way to get through is by saying the password of the week. Once inside you will see that the Gryffindor common room was circular around the room were tables and chairs/couches. There are windows that when looked through you could see the Hogwarts grounds. There was a big fireplace that had a portrait of a lion on the mantel. The common room was usually not full of people except in the dead of night.

Hufflepuff Common Room

The Hufflepuff common room is located in the kitchen hallway. The common room can only be accessed by choosing barrel two from the bottom middle of the second row in the rhythm of "Helga Hufflepuff". If you answer it correctly the barrel lift will open and you can enter however if you get it incorrectly you will be doused with vinegar and barred access. In the common room, you can see it is decorated with bee-like colors of yellow and black. With honey-colored tables and round doors that lead into the boy's and girl's dormitories. Various cacti are at the windowsill and wave at passersby. A portrait of Helga Hufflepuff hangs over the wooden mantel. 

Ravenclaw Common Room

The Ravenclaw common room is at the Ravenclaw tower. The only way to enter the common room is by knocking on the knocker. It will ask you a riddle and you need to answer it. if you get it correctly you may enter however if you get it incorrectly you have to wait until someone else comes and answers it correctly. The common room was draped with blue felt everywhere. 

Slytherin Common Room

The Slytherin common room is down in the dungeons. How you would enter the common room by using the door to the right side of the Entrance Hall. The entrance would only open if you say the correct password and then the entrance will open leading to the common room.