Ar is the most populous city on Gor though there are not fully accurate figures for its exact population. An accurate census of its population does not seem to be a concern. A reasonable estimate of its free citizens is thought to be about two and three million. There is also approximately another quarter of a million non-citizens who reside in the city. In addition, there is also approximately a quarter of a million slaves, primarily women. This means that roughly 15% of the female population of Ar are slaves, a percentage much greater than the Gorean norm of 2% to 3%. Please remember that these figures reflect only the population of the city itself and does not include the population of all of the lands under the control of Ar.

Ar is far more than a simple city. It is a small empire in its own right, a central city that controls twelve other cities, the Twelve Tributary Cities. These cities came under the hegemony of Ar during the early reigning years of Marlenus. Some of these cities are located north of Ar but no description, name or location is given for these twelve cities. The Home Stones of these cities are kept in the Central Cylinder of Ar. Some of these cities aided Master Assassin Pa-Kur when he besieged Ar, hoping to gain their independence. They failed and remain under the hegemony of Ar.

The actual physical size of Ar is never given though it must be quite large, containing thousands of cylinders. It is at the very least, several pasangs in diameter. Ar is surrounded by double walls of stone, though parts of those walls were destroyed by Cos during the events of Magicians of Gor. The stones were transported elsewhere for construction work. The outer wall was about three hundred feet high while the inner wall was about four hundred feet high. The two walls were separated from each other by a distance of about sixty feet. Every fifty yards on the walls was located a guard tower. Each wall was very wide, sufficient for six tharlarion-driven wagons to travel side by side. After the events of Assassin of Gor, the city walls were painted white so that the sun would cause a glare to bother anyone attempting to attack or besiege the city. At night, fires were lit at certain areas on the walls to act as beacons for tarnsmen. Tarn wires were often kept in place over the city to prevent raiding tarnsmen from entering the city.

There are a number of gates in the walls to permit entrance into Ar. There are forty public gates and an unknown number of smaller gates where entrance is restricted. There are even some secret gates, known only to a few. The great gate of Ar, the largest of all of the gates, leads directly to the Viktel Aria. Within the city, the great gate open onto the Avenue of the Central Cylinder and heads north to the Central Cylinder itself. The great gate is made of strong wood and is plated with metal. Unfortunately this gate was destroyed by Cosians in Magicians of Gor. It appears that the great gate is a sun gate, which means it is only open from dawn to dusk. At night, it closes and would-be entrants must seek out another gate. The Tarn Gate is Ar's west gate. The rest of the gates are not named in the books. - City of Ar (Luther).