Mamoré River
Guajará-Mirim lies along the Mamoré River, just across the Bolivian border town of Guayaramerín. It was once the southern terminus of the Estrada de Ferro Madeira-Mamoré (the Madeira-Mamoré Railway), which was inaugurated in 1912. It is the seat of the Roman Catholic Diocese of Guajará-Mirim.