Geological features

Lastovo and its archipelago are made of Jurassic and Cretaceous sediments made primarily by dolomite, dolomite limestone, and pure limestone.

The highest peak of the island of Lastovo, Hum (417 m), is the most beautiful observation point on the island; it boasts a view of the variety of the landscape, with its rolling hills, deep bays and fields, and also an infinite view of the sea and the islands. The peaks of Mali Hum (415 m) and Pleševo brdo (400 m) are somewhat lower.

Morphologically, the series of separate forested hills and karst bays – fields is noteworthy (the largest fields are Vinopolje, Lokavje and Prgovo), which were created in impermeable zones of dolomite or semi-permeable dolomitic limestone.

The karst composition of Lastovo was favourable for the creation of caves. The most popular cave is the Rača cave in the south-eastern park of the island, which was protected as a geo-morphological monument of nature and an archaeological site in 1965, and Medjedina, once the habitat of the Mediterranean monk seal, which is today known for large populations of bats.