Ostalpen
The Eastern Alps are divided into four main areas: the Northern Limestone Alps, the Central Eastern Alps, the Southern Limestone Alps, and the Western Limestone Alps. These four main ranges are further divided into 75 sub-groups. The Northern Limestone and Central Eastern Alps are the largest with 27 groups each, while the Southern Limestone Alps have 15. The six groups of the Western Limestone Alps are also classed with the Central Eastern Alps.