Situated on a large Mediterranean Sea gulf (the Gulf of Tunis), behind the Lake of Tunis and the port of La Goulette (Ḥalq il-Wād), the city extends along the coastal plain and the hills that surround it. At its core lies its ancient medina, a World Heritage Site. East of the medina through the Sea Gate (also known as the Bab el Bhar and the Porte de France) begins the modern city, or Ville Nouvelle, traversed by the grand Avenue Habib Bourguiba (often referred to by popular press and travel guides as "the Tunisian Champs-Élysées"), where the colonial-era buildings provide a clear contrast to smaller, older structures. Further east by the sea lie the suburbs of Carthage, La Marsa, and Sidi Bou Said. As the capital city of the country, Tunis is the focus of Tunisian political and administrative life; it is also the centre of the country's commercial activity.
Tunis is the transcription of the Arabic name تونس which can be pronounced as "Tūnus", "Tūnas", or "Tūnis". All three variations were mentioned by the Greek-Syrian geographer al-Rumi Yaqout in his Mu'jam al-Bûldan (Dictionary of Countries).
Different explanations exist for the origin of the name Tunis. Some scholars relate it to the Phoenician goddess Tanith ('Tanit or Tanut), as many ancient cities were named after patron deities. Some scholars claim that it originated from Tynes, which was mentioned by Diodorus Siculus and Polybius in the course of descriptions of a location resembling present-day Al-Kasbah; Tunis's old Berber Bourgade.
Another possibility is that it was derived from the Berber verbal root ens which means "to lie down" or "to pass the night". Given the variations of the precise meaning over time and space, the term Tunis can possibly mean "camp at night", "camp", or "stop". There are also some mentions in ancient Roman sources of such names of nearby towns as Tuniza (currently El Kala), Thunusuda (currently Sidi-Meskin), Thinissut (currently Bir Bouregba), and Thunisa (currently Ras Jebel). As all of these Berber villages were situated on Roman roads, they undoubtedly served as rest-stations or stops.
The historical study of Carthage is problematic. Because its culture and records were destroyed by the Romans at the end of the Third Punic War, very few Carthaginian primary historical sources survive. While there are a few ancient translations of Punic texts into Greek and Latin, as well as inscriptions on monuments and buildings discovered in North Africa, the main sources are Greek and Roman historians, including Livy, Polybius, Appian, Cornelius Nepos, Silius Italicus, Plutarch, Dio Cassius, and Herodotus. These writers belonged to peoples in competition, and often in conflict, with Carthage. Greek cities contended with Carthage over Sicily, and the Romans fought three wars against Carthage. Not surprisingly, their accounts of Carthage are extremely hostile; while there are a few Greek authors who took a favourable view, these works have been lost.