Lake Ira Lalaro (also Iralalaro, Ira-Lalaro, Surubec, Suro Bec) is a waterway in Mehara, Subdistrict Tutuala, Lautém District of East Timor. It is the largest freshwater lake on the island of Timor, and the largest lake in the country of East Timor. The lake is part of the Mount Paitchau Important Bird Area. The lake waters and that of Irasiquero River are a closed aquatic system; they lie within a huge polje. The surface water area fluctuations from 10–55 square kilometres (3.9–21.2 sq mi) while the authigenic catchment area measures 406 square kilometres (157 sq mi).