The Free State of Thuringia (German: Freistaat Thüringen) is a federal state of Germany, located in the central part of the country. It has an area of 16,171 square kilometres (6,244 sq mi) and 2.29 million inhabitants, making it the sixth smallest by area and the fifth smallest by population of Germany's sixteen states. Most of Thuringia is within the watershed of the Saale, a left tributary of the Elbe. Its capital is Erfurt.
Thuringia has been known by the nickname of "the green heart of Germany" (das grüne Herz Deutschlands) from the late 19th century, due to the dense forest covering the land.