The nuraghe or nurhag is the main type of ancient megalithic edifice found in Sardinia, developed during the Nuragic Age between 1900 and 730 B.C. Today it has come to be the symbol of Sardinia and its distinctive culture known as the Nuragic civilization. More than 7,000 nuraghes have been found, though archeologists believe that originally there were more than 10,000.
Natively, the structure is called a nurhage (nuˈɾaɣɛ, nuˈraːɡe; plural: Logudorese Sardinian nuraghes, Campidanese Sardinian nuraxis nuˈɾaʒizi, Italian nuraghi).
According to the Oxford English Dictionary the etymology is "uncertain and disputed": "The word is perhaps related to the Sardinian place names Nurra, Nurri, Nurru, and to Sardinian nurra 'heap of stones, cavity in earth' (although these senses are difficult to reconcile). A connection with the Semitic base of Arabic nūr 'light, fire, etc.' is now generally rejected." The Latin word murus ('wall') may be related to it, being a result of the derivation: murus–*muraghe–nuraghe. However, such theory is debated.
An etymological theory suggests a Proto-Basque origin by the term *nur (stone) with the common -ak plural ending; the Paleo-Sardinian suffix -ake is also found in some Indo-European languages such as Latin and Greek. Another possible explanation is that the term nuraghe came from the name of the Iberian mythological hero Norax, and the root *nur would be an adaptation of the Indo-European root *nor.
The typical nuraghe is situated in areas where previous prehistoric Sardinian cultures had been distributed, that is not far from alluvial plains (though few nuraghes appear in plains currently as they were destroyed by human activities such as agriculture, dams, road building etc.) and has the outer shape of a truncated conical tower, thus resembling a medieval tower, with a tholos-like vault inside.