evidence: fresh water lake(s): Lagoa dos Patos - 10,140 sq km salt water lake(s): Lagoa Mirim (shared with Uruguay) - 2,970 sq km [...] Brazil-Bolivia: the Roboré Accord of March 29, 1958 placed the long-disputed Isla Suárez/Ilha de Guajará-Mirim, a fluvial island on the Río Mamoré, between the two towns of Guajará-Mirim (Brazil) and Guayaramerin (Bolivia), under Bolivian administration but did not resolve the sovereignty dispute [...] Brazil-Uruguay: the uncontested boundary dispute between Brazil and Uruguay over Arroyo de la Invernada triangle and sovereignty over Isla Brasilera leaves the tripoint with Argentina in question; smuggling of firearms and narcotics continues to be an issue along the Uruguay-Brazil border