Madre de Dios is a department and region in southeastern Peru, bordering Brazil, Bolivia and the Peruvian departments of Puno, Cusco and Ucayali, in the Amazon Basin. Its capital is the city of Puerto Maldonado. It is also the third largest department in Peru, after Ucayali and Loreto. However, it is also the least densely populated department in Peru, as well as its …Madre de Dios is a department and region in southeastern Peru, bordering Brazil, Bolivia and the Peruvian departments of Puno, Cusco and Ucayali, in the Amazon Basin. Its capital is the city of Puerto Maldonado. It is also the third largest department in Peru, after Ucayali and Loreto. However, it is also the least densely populated department in Peru, as well as its least populous department. It has one of the lowest poverty rates in Peru.