Batna located between the north and the south Atlas Mountains started life as a French military fortress, built in 1844 to enable the French to control access between the Sahara and the Atlas Mountains along the Kantara Pass.
At an altitude of a thousand metres, Batna is known for having a fairly extreme climate with scorching dry summers and bitterly cold winters with snow being a reasonably common occurrence.
When you visit Batna, make sure you visit the nearby ruins of Timgad and Lambaesis. Both ancient Roman cities, show how far-reaching the effects of Roman rule really were.
Timgad, built around the 1st century, had an essential role in the control of commerce in those early times.