Tangkoko Batuangus Nature Reserve, Indonesian: Tangkoko-Batuangus Dua Saudara is a nature reserve in the northern part of Sulawesi island of Indonesia, 70 kilometres from Manado City. The reserve covers an area of 8,718 hectares, and includes three mountains: Mount Tangkoko at 1,109 metres, Mount Dua Saudara at 1,361 metres, and Mount Batuangus at 450 metres.