The Bay of Kaštela is surrounded by mountains Kozjak, Opor and Trećanica. The mountains gentle slope to the sea. Highest and longest among them is Kozjak. It stretches 16 kilometers in length from Klis on the east to the Malačka saddle to the west. Its rocky part along the ridge, the longest in Croatia, is impressive, but not its height (50 – 250 m). The highest point is Veli vrj - 779 m.

Vegetation of Kozjak is interesting. There are myrtle, Spanish broom, strawberry-tree and other plants characteristic for Mediterranean low vegetation on the southern slopes. To the north we meet black and white hornbeam, black ash, oak and other species distinctive to sub-Mediterranean flora. There are a number of endemic plants on Kozjak and among them the orchids.

There were many caravan trails through Kozjak in the past. There is ca 80 km of marked mountaineering paths through Kozjak and neighboring mountains suitable for recreational mountaineering. The rocks of Kozjak are well-known for rock-climbing routes (some of them are near the "Malačka" mountaineering house). These routes are not demanding and could be climbed by recreational mountaineers.

A fire-fighting road traverses slopes of Kozjak from east to west making each mountaineering house accessible by bike.

The “Mountaineering Path of Dalmatia" and the “Mountaineering Path Cradle of Croatian Statehood Bijaći – Klis" lead along the highest points of the mountains of Kaštela. There are 19 control points along the 30 km of paths. These control points are mostly at sacral objects built in the time of Croatian people\'s rulers (St. Marta at Bijaći, St. Nofar, Stomorija, St. Juraj od Raduna, St. Ivan Biranj, St. Kuzma and Damjan, St. Juraj od Putalja and other) till its end at Šuplja crkva (Hollow church) in Solin. It is rare to find four mountain houses (Putalj in Kaštel Sućurac, Koludar in Kaštel Kambelovac, Split and Malačka in Kaštel Stari), a mountain refuge (Orlovo gnjezdo in Kaštel Kambelovac) and a hunting house at such a small area, where mountaineers can get refreshment or a place to sleep.

Mountaineering association would be glad to provide mountain guides to groups and individuals and enable them to enjoy view at Kaštela, the Bay of Kaštela, Trogir, Split, Central Dalmatian islands and the Kaštela Hinterland.