The largest lake of Järva County, Lake Väinjärv, is located four kilometres from Koeru on the southern edge of Pandivere Heights in the centre of Estonia. Lake Väinjärv covers a surface of 41.5 ha and is up to 11.5 metres deep.
A beach and a swimming area, as well as a diving tower, and a boat rental are located on the northern shore of the Lake Vainjärv. In the summer, there is also an ice cream booth for children, as well as swings.
A large camping area and fire pit are also located on the shores of Lake Väinjärv. A spectacular water festival is held on Lake Väinjärv every year in July. Lake Väinjärv is also a favourite among anglers.