Slovakias unique natural heritage are represented in the UNESCO World Heritage List by caves and abysses of Slovenský kras karst and by Dobšinská ľadová jaskyňa cave. In 2007 the Carpathian primeval beech forests of the Bukovské vrchy and Vihorlatské vrchy Mts. in the east of Slovakia were added to this list.
Slovenský kras situated in the south of Slovakia on the frontier with Hungary is the largest karstic area in the middle Europe. It consists of 1110 caves and abysses.
In 1995 the bilateral Slovak-Hungarian project with the title Caves of the Slovak and Aggtelek Karst (Ochtinská aragonitová jaskyňa, Gombasecká jaskyňa, Jaskyňa Domica, Krásnohorská jaskyňa, Jasovská jaskyňa, …) was successful in its endeavour to be included among the most precious world natural phenomena. In 2000 this inscription also included the ice cave of Dobšinská ľadová jaskyňa, one of the largest of its kind in Europe.
The primeval beech forests of the Carpathians in the Ukraine and in Slovakia were added to the UNESCO World Heritage List in June 2007. Thanks to this fact, the Carpathian primeval beech forests of Stužica, Rožok and Havešová in the Bukovské vrchy Mts. and Vihorlatský prales primeval forest in the Vihorlatské vrchy Mts. in CHKO Vihorlat are of world importance. The first three of them are situated in the area of the Poloniny National Park.
The Slovak Republic prepared further nominations for this List and among them is the Tatra National Park, the National Park of Slovenský raj and the National Park of Malá Fatra.