The southern part of the Iberian Peninsula, known as Hispania Ulterior, was a complex area in which the cities opted for different scripts for their monetary issues, choices that reflected their varied cultural foundations and also the growing Roman presence.
A small group used indigenous scripts, which are not always easy to read. These use the southern variant of Iberian script, except for the coins from Salacia (Alcácer do Sal, Setúbal, Portugal), which provide the only evidence of their own script, also known as Sudlusitan.
The two most important mints in this group - and also the first to begin striking coins, perhaps in the late 3rd century BCE - were Castulo and Obulco, in the province of Jaén, two powerful centres thanks to their control of mines and agricultural areas. As in the rest of Iberia, most of the cities that issued coins did so between the 2nd and mid-1st centuries BCE, always in bronze but in varying quantities. Most of them gradually integrated Latin script.
The reverse of the Castulo coins - a sphinx with a distinctive pointed headdress - inspired the sculptures that flank the Museum's door, the work of Felipe Moratilla (1893-1894).