The oldest fragments of the Slovak mountains are the central part of the Western Carpathians. The youngest are located in the south of the country and come from the Quaternary.

An excerpt from the article 37 facts about Slovakia

The highest mountain range in the Carpathians is the Tatra Mountains with 29 peaks higher than 2500 m above sea level. They cover an area of 750 square kilometers, most of which - 600 square kilometers - is located in Slovakia. They are divided into several parts. In the north, near the Polish border, are the High Tatras, a popular hiking and skiing destination and home to many picturesque lakes and valleys. Their highest peak is Gerlach. The Tatra Mountains are represented as one of three hills in the coat of arms of Slovakia.