Arica is part of a dense socio-historical skein that form the Chilean borders, but distinguished by the particular intensity and diversity of its fields and circuits of cross-borders relationships. Its reality as a transborder region - molded by the actions from communities, markets and states is a peculiar interweaving of its relations with its three land borders: Bolivia, Peru and Tarapaca. And with its port, that connect the region with the Pacific Ocean and the Asian economy. This article discusses the characteristics of each one of them, the way they relate to create a distinguishable territory and the challenges that implies for the future development of the region.