[1] The association has been made principally from the analysis of classical sources in the early 20th century by Adolf Schulten.
[1] The first description of the city of Mastia appears in a poem entitled Ora Maritima (Sea Coasts) by the Latin poet Rufius Festus Avienius from the 4th-century AD.
The description of Avienus reads: ... then is Namnatius portus that from the sea opens its curve near the town of Massienos, and at the bottom of the Gulf rise the high walls of the city of Massiena ...
Context and other geographic descriptions that precede and follow these lines suggest that it could refer to the same location.
locate Mastia somewhere near the ancient city of Carteia (near modern Gibraltar), at the head of the Bay of Algeciras.