Most of the rooms have a window or a door to the main yard. This is the place where the inhabitants of the castle used to cook. The way rooms are disposed make experts thing that this castle was not only used for defense, but also for a califal resiednce, specially because of the ornaments in plaster of the inner rooms.
A walk around the different rooms inside the castle is a nice experience. There are several sized rooms,also baths (as it is a very important thing in arabic culture) distributed in 2 floors around the main and only yard. All that castle is transitable, even the terrace at the roof.
There are still many debate about which was the original function of the building. The most widely accepted opinion among scholars is that it was a khan, or inn. If this were true then Qasr al-Kharanah would be the earliest known khan of the Islamic period.
The rooms and halls of the upper floor basically repeat the ground plan except for the room on the south side, that is above the main entrance. Stucco discs with stylized plants decorating the upper sections of the some rooms reflect close contact with the art of Iraq or Mesopotamia.
The courtyard had a basin for collecting rain water at its centre. Originally it was surrounded by a portico supported by arches. In the southeast and southwest corners of the courtyard are stone staircases leading to the upper floor and roof.
At the ground floor there is a central courtyard that can be reached from the entrance through the passage which is flanked by the storage halls two dimly lit rooms whoose barrel vault roofs are supported by transverse arches. The open central courtyard is surrounded by groups of barrel vaulted rooms forming separate units, each unit consisting of acentral hall flanked by two rooms in either side. This arrangement is knowns as a bayt in Umayyad architecture.
The Qasr al-Kharanah consists of two floors with a square plan, 35 metres on each side. Round buttresses occupy the four corners and semi-circular buttresses occupy the centres od the walls, excepts for the southern wall which has the only entrance to the building. Narrow openings in the outer walls appear to be arrow slits at a passing glance. However they actually serve to provide light and ventilation to the interior.
The building of Qasr al-Kharanah is well preserved with its original architectural elements, its date and original function are still issues of debate among scholars. And Arabic inscription in black ink and several lines long, was found on the plaster above on of the doorways in the main hall of the upper floor. It was written in the November 710 AD, during the reign of the Umayyad caliph al-Walid ibn 'Abd al-Malik.
You can notice many stones with Greeek inscription on the main doorway, and scholars thing that it was built over a Roman or Byzantine building.
Access to Qasr al-Kharaneh costs one dinar, which allows you access to all the other desert castles on the same ticket.
You can also walk some stairs up to the roof, which has been restored and now you can walk around it and have views from the entire structure, as well as from the yard and from the wide horizon.