The Sinyaya (Russian: Синяя; Yakut: Сиинэ, Siine) is a river in the Sakha Republic, Russia. It is a left tributary of the Lena. It is 597 kilometres long, and has a drainage basin of 30,900 square kilometres.
The river begins in the Tampa-Ottoowo, a small lake located in the Lena Plateau at an elevation of 278 metres. It flows roughly southeastwards and there are about 3,300 lakes in its basin. In its lower course the river is flanked by picturesque rock formations, the Sinyaya Pillars. The Sinyaya meets the left bank of the Lena near Sinsk, 150 km upstream from Yakutsk and 1,716 km from the Lena\\\\\\\’s mouth.
The Sinyaya freezes between October and May. From the end of May to June it flows at a high level owing to the melting of snow and the flow recedes in the summer. The area of the river basin is largely uninhabited. The river flows across three districts, Verkhnevilyuy, Gorny and Khangalassky.
