The functional definition proved to be a harder nut to crack. The first approach is to look at the buildings needed for an urban lifestyle; however, the current state of art does not allow for a complete study of the ‘foundation kit.’ At the moment, macro-scale studies into several of the buildings, such as the forum and thermae , are still missing. The development of the settlement system cannot be fully understood without examining the pre-Roman settlement system. Basically, two different settlement patterns can be distinguished in the pre-Roman period. On the one hand, people observe that the city-state model is found in the eastern coastal areas of the Iberian Peninsula. In the inland regions, people find the tribal state organisation. The tribes converged on one central fortified urban or proto-urban place with subordinate castros. This pattern can be recognised for the regions of the Meseta Central and the Ebro valley.