The Val Rosandra, a Regional Protected Area on the border with Slovenia is a deep limestone valley cut into the Carso rock, where woodland and vertical rock-faces meet scree-slopes, heaths and moorland.
Thanks to its unusual characteristics of form and geographical position, the area has been recognized as a geological site of worldwide importance and is still the subject of scientific study, as well as being popular with climbers, walkers and the pot-holing community.
The valley is crossed by the seasonal river of the same name, the Rosandra, which is the only example of surface water on the Triestine
Carso and is an important source for the life of local flora and fauna. Here can be seen a wide variety of birds, reptiles and amphibians, and animals such as hares, deer, foxes and dormice.
The river creates a spectacular waterfall of 30 metres in height, and at various points deep cracks in the rock-faces open out to enable us to explore an intriguing and complex underground world. Over a hundred such openings have been discovered, some of which were inhabited in the prehistoric past, and important archaeological finds have been made in the so-called Gallery Cave (Grotta delle Gallerie).
The two castellieri built on Monte Carso and San Michele date back to proto-historic times, while at the mouth of the valley can be seen remains of the Roman aqueduct which carried water to the ancient Tergeste and fed a fountain located in the present-day Piazza Cavour in the very heart of Trieste.
The main footpath through the area starts from the village of Botazzo where there are still the remains of several mills. From there walkers can climb to the memorial stone erected to the memory of the legendary Triestine mountaineer Emilio Comici, to the mountain peak of the heights of San Lorenzo with their panoramic view over valley, the sea and the western slope of Monte Carso.
As if suspended on the crest stands the picturesque chapel of Santa Maria in Siaris, a place of pilgrimage which has often been re-built.

Point of interest
The Visitors' Centre of the Protected Area of the Val Rosandra is housed in the village of Bagnoli della Rosandra-Boljunec, the gateway to the valley, and offers information and suggested footpaths to help visitors to learn more about this unique environment.
Because of the numerous differing characteristics of the area, there is an unusually wide range of bio-diversity with rare, precious species of both flora and fauna, for example plants such as the Moehringia di Tommasini and the Genista holopetala (scree-broom) and wildlife such as the fresh-water shrimp and several species of bat.