The region known as Cabeça do Cachorro (Dog‘s head) is the area comprising the northwesternmost end of the state of Amazonas, Brazil, bordering on Colombia and Venezuela. This region roughly coincides with the Brazilian municipality of São Gabriel da Cachoeira and parts of Japurá, and shares international borders with the Venezuelan state of Amazonas (to the northeast), and the Colombian departments of Guainía (to north), Vaupés (to west) and Amazonas (to southwest). The Brazilian Army maintains a border platoon next to the border tripoint, at the village of Cucuí, where there is also a Brazilian Air Force base.