The basic underlay underneath Gaslicica is made up of silica dating from the Paleozoic period.  Over them there is a massive porous limestone with a thickness of 500-550m.  This type of geological structure and the existence of geomorphologic rock formations, make this mountain resemble the mountains from Deaneries mountain range.  On Galicica there can be found different types of landscape fields, surface rock formations, as well as, underground formations such as caves and crevices.     

Geological underlay and morphology of the mountain influence to a great extent the beauty of the scenery and aesthetic values of the park.  Furthermore, they are one of the underlying conditions for existence of wide wildlife biodiversity.

Due to the inability of the limestone layer to hold water, Galicica is one of the driest mountains in Macedonia.  In the upper sections of the mountain there are only few permanent water springs producing small quantities of water.  Sometimes in years with high amount of precipitation new water springs appear in spring time, and dry out in summer.

On the other hand the foothill of the mountain near the Lake Ohrid is abundant with water springs.  Water springs at “St. Naum” monastery are typical example. They are made up of thirty underwater, and fifteen near the shore springs with total water capacity of 7.5 cubic meters per second.  These springs form small lake pool of 30ha and maximum depth of 3.5m.  There are two small islands in this small lake.  Latest surveys performed with a use of natural radioactive isotopes, have confirmed the proposition that some of the water produced by these springs originates form Lake Prespa which is 150m higher than Lake Ohrid.  Apart from the geological and hydrological characteristics this area is made even more attractive by having wide variety of plants and animals.

On the very edge of the National Park there are “Biljanini Izvori”, springs location in the vicinity of Ohrid, very popular with visitors.