In 1990 the first remains of what would be one of the most interesting monuments of the city of Cartagena were discovered accidentally. It is one of the largest and most comprehensive theatres throughout Spain.
It was built in 44 BC when Octavian Augustus was emperor and Cartagena was a Roman colony (Colonia Urbs Nova Carthago) going through a period of high population and economic development; at that time it was called Carthago Nova. From its location, the theatre has witnessed different periods of the history of Cartagena, since the Roman Empire, up to the present, overlapping constructions of each of the historical periods. The Roman Theatre faithfully followed the theatre model proposed by Vitruvius. It was built almost entirely in the rock on a hill.
https://www.murciaturistica.es/en/monument/teatro-romano-349/