Lake Ōnuma (Wakkanai)

Ōnuma (大沼) is a low-lying lake in Wakkanai, Hokkaidō, Japan. Its surface area of 4.67 sqkm makes it, by this metric, the twentieth largest on the island. Located a short distance inland from Sōya Bay (宗谷湾), with the city centre to the west and Wakkanai Airport to the east, Ōnuma provides a resting point in the autumn for swans from Siberia on their way to their winter grounds, and again in spring upon their return.