Clunia

Clunia (Colonia Clunia Sulpicia) was a major Roman city on the Alto de Castro near Peñalba de Castro, Burgos, at over 1,000 metres elevation. Founded ex novo under Emperor Tiberius on a site of Celtiberian (Arevaci) origins, it became capital of the Conventus Cluniensis in Hispania Tarraconensis. Galba proclaimed himself emperor here in 68 AD during the anti-Neronian revolt. The urban complex extends over 130 hectares, featuring a rock-cut theater seating 10,000, a forum, public baths, and the Cueva Roman underground water system with inscriptions on raw clay. The city reached c. 30,000 inhabitants at its peak before declining in the 3rd century.