“Bulwark on top of the Alps”

The remains of the claustra Alpium Iuliarum barrier system are the largest Roman monument in Slovenia. Its construction began in the second half of the 3^rd century, but was fully realized in the Constantine period (first half of the 4^th century). It fulfilled its role until the 5^th century when it lost its importance.

Prior to the construction of the Ad Pirum military fort, the remains of which are still winding on the slopes of the Listnik Hill, the Romans set up a postal and relay station on this spot. It was built simultaneously with the Roman state road during the time of Emperor Augustus (27 BC–14 AD). The new road through Ajdovščina and Hrušica, connecting Aquileia (Italy) and Emona (today’s Ljubljana), replaced the previous longer road through Razdrto and shortened the journey between these two cities for two travel days. From the 2^nd century onward, there was also an adjutant (some sort of police) post located here.

In the late 3^rd century, the Romans enclosed the postal station with a mighty military fort and stationed a military crew in it. At that time, the long period of peace and prosperity was shaken by the invasions of various Germanic and barbaric peoples who were conquering and pillaging the territory of the Empire. To control the routes to Italy, a barrier system, now known as claustra Alpium Iuliarum, was built, which also included the fort on the Hrušica Plateau.

The ground plan is adapted to the land and has an irregular oval shape. The fort is 250 m long and up to 75 m wide. It is surrounded by a 2.7 m thick wall, which was about 8 m high and fortified with towers. The transverse wall with a narrow passage, which divided the fort into a lower and upper part, was also fortified with towers. The purpose of the upper part of the fort is not fully understood, while in the lower part, there was a staff building with military barracks and tents. In that area, there were also small workshops and repair shops, a postal station, a cistern and tents. In the places where the fort was intersected by the Aquileia–Emona road, the Romans set up a gate, surrounded by two towers about 10 m high.

Take a walk on the archaeological trail leading along the remains of the Late Roman barrier system! The remains of the wall in the area are today visible as a metre high embankment. The 4 km long archaeological trail leads along the remains of the Roman wall and towers and continues on a macadam forest road leading back to the fort. Along the way, there are interpretative boards and direction columns, which mimic the shape of the Roman mileposts that were located at the side of the roads where you can discover many interesting facts.

WARNINGS: Walking at your own risk. Stay on the marked trail due to the danger of abysses. We recommend suitable footwear, clothing and appropriate protection against ticks. On some sections of the trail, the descent and ascent are steep. Weak mobile signal. Bear area. Do not pollute nature!

Morimus funereus is an up to 4 cm large beetle with an elongated body, of grey-blue colour, with two black spots on each elytron. It has very long antennae. It feeds on the wood of various tree species. Adult animals are attracted by the scent of wounded or felled trees, especially beeches and fir trees, where females also lay eggs. The development lasts three to four years and the larvae feed under the bark and pupate deeper in the wood. The little beetles are wingless, but they walk well.

You are standing on what used to be a Roman side road, which enabled good communication between individual hamlets. On this road, the attackers could circumvent the Ad Pirum fort along the main road to avoid military surveillance in the area. They were unsuccessful because Roman soldiers also protected this part of the route with a tower and a gate, which prevented free passage. The remains of the tower are still visible on the left and right side of the road. The Roman side road also leads past the so-called Ice cave, in which ice remains throughout the year. The inhabitants of the Ad Pirum fort could store larger supplies of food in the cave or use the ice from it in some other manner.

In Roman times, the state was responsible for the construction of important roads, which were mostly built by soldiers. The roads were laid out in a straight line as much as possible or adapted to the terrain. The roads were routed across bridges to cross the rivers and tunnels were built as well.

Fully equipped soldiers and travellers who travelled on foot could travel about 30 km a day. A far greater distance could be travelled in one day by the troopers who changed horses at the stations (100 to 300 km). Cargo travelled slower in ancient times. Post carts travelled about 70 km a day, while ox yokes only 6 – 14 km, depending on the weight of the cargo.

The forest reserve Veliki Bršljanovec is a well-preserved remainder of beech-fir forests on the Hrušica Plateau. It lies at the foot of the hill with the same name. Its surface covers 12 ha. The reserve has not been cultivated since 1978, so we can observe how the forest behaves when people do not interfere with it. In the last 20 years, we have seen the decay of the fir trees and the number of dead trees accumulating, which attracts especially woodpeckers and insects.

The main elements of the Late Roman barrier system claustra Alpium Iuliarum were the mighty stone walls, additionally fortified with towers, with forts or fortlets positioned at important crossings. The remains of the walls can today be seen only as embankments, covered with soil and undergrowth, usually hidden deep in the forests. Initially, the wall probably measured 3 – 4 m in height and was protected by towers. Nevertheless, in some places, the parts of the barriers are better preserved or even partially reconstructed, revealing their former image. The Ad Pirum fort in Hrušica is also one of them.

In the 3^rd and 4^th centuries, the Roman Empire was shaken by unrest. Several civil wars followed and invasions of the barbaric peoples who lived on the borders of the Empire were more and more frequent. In this turbulent time, it was relatively easy to get to power, but it was much harder to keep it. Many emperors reigned for only a few months. In these circumstances, the Roman army experienced numerous changes, which also reflected on the attire and equipment of a Roman soldier. The novelties included long loose trousers, closed leather shoes or boots and a long-sleeved tunic, which was usually decorated. On top of the latter, the soldiers wore a chain mail or scale armour and a helmet on their heads. A long straight sword replaced the short one. More often than a long spear, the soldiers carried in their hands different types of light spears or lead-weighted darts, which could be thrown up to 65 m away. They carried them pinned to the back of a large oval shield.

Serving in the Late Roman army lasted about 20 years. Individuals entered it voluntarily, while the enlistment became more and more frequent. To avoid military service, young men often deliberately mutilated themselves – they would cut off their thumb. Emperor Theodosius (379–395) prevented the deception with the rule stating that 2 mutilated soldiers equal 1 healthy soldier. Due to difficult living conditions and relatively low wages, many soldiers also deserted.

What is also characteristic for the Late Roman army is that many of its soldiers were barbarians. In contrast to the Romans, they were less loyal, which led to the descent of power of the Roman army.

The tower next to which you are standing is one of the nine towers that served for the observation and protection of the Late Roman fort. The remains of a side door are clearly visible next to it.

As the original quadrilateral tower was destroyed, a new, five-angle tower was built in the same spot. Use the side door and take a look!

The violet flowering Spring Crocus is one of the earliest heralds of spring. On the Hrušica Plateau, we can observe a white subspecies, which also bears the name of Albiflorus (Slovenian: “nunka”). It grows on lawns and in snow hollows, where the ground is humid, cold and rich in nutrients. Saffrons are one of the first spring pastures, which wild bees also like to visit.

The fort on the Hrušica Plateau was included in the system of barrier walls, which can today still be traced to the north and the south. From the southern corner of the fort, where you are now, two branches extended in the directions of the southeast and the southwest. Roughly a kilometre-long south-eastern branch ran towards Veliki Bršljanovec, a saddle-shaped hill, which you can see in front of you. Fortified with a large gate tower, it closed the valley through which a Roman side road ran, thereby preventing bypassing manoeuvres of attackers. The southwestern branch, which was weaker and is today only preserved in the length of 60 m, guarded the back of the defenders against attacks from the direction of the Postojna Basin.

You are standing in the part of the fort where wooden and brick buildings once stood. One of them stands out as being especially outstanding because it had a furnace! The warm air circled inside it through clay pipes in the walls. Such a Roman heating system is called a hypocaust.

In the first half of the 15^th century, a gothic church was built in an abandoned fort, at the site of an older church from the 12^th century. It was dedicated to St. Gertrude, the patron saint of travellers. If you follow the stone wall, you can see the foundations of a semi-circular arched space. This area, which we call the apse, was the most important area of the church. The altar was usually located in it.

From the first century onwards, there was a postal station ion this spot, the remains of which are not visible today. Roman postal stations can hardly be compared with modern post offices, since they were some sort of roadside rest areas, similarly as the present-day motels. Travellers could spend the night in them, replenish their strengths or change animals to continue the journey. They usually stood at distances that could be travelled in one day.

Almost on the same spot as today, a new main traffic connection ran in Roman times. It replaced the old road across Ocra (today’s Razdrto) and shortened the journey between Emona (today’s Ljubljana) and Aquileia for at least a day. At the end of the 3^rd century, the Romans built a military fort at the highest passage over it, thus closing the free passage. A traveller crossed the road through the mighty double gate, protected by high towers.

The transverse wall with towers divided the fort into lower and upper parts. On the spot where you are standing, there was a passage, which was fortified with an arched tower. A 5.3 metres long and 3.3 metres wide passage led through the tower. The upper part of the fort was used as a livestock pasture and tactical withdrawal of the army in case of occupation of the lower part. In the event of extreme danger, soldiers could escape the fort through an emergency exit at the far northern edge of the fort, which is still visible today.

When the sun warms up the air and the ground, wild bee females look for suitable nest sites. They make their nests in the ground, so we notice them when they fly low above them. Each female builds her own nest, lays some eggs (about 10) in it, from which the workers hatch who help the young queen bee create a small family. In the autumn, all members of the family die, only numbed queen bees survive in the ground nests. They do not make honey supplies, because there is no one to eat it in the winter.

In the event of occupation of the fort, soldiers had no other choice but to flee. They could escape the fort through a narrow emergency exit you see in front of you. On the other side as well, the barrier wall protected them against enemies on one side, which continued along the slope. Test the width of the door and estimate how many soldiers could go through at the same time!

Beech is the most common tree in Slovenia. In the future, there will be even more of it as it will replace spruce, which has been planted since the 17^th century. In the lowlands, it reaches up to 40 meters in height, but here in Hrušica, due to more demanding living conditions, it is lower in growth. At the contact of the humid and warm air of the Primorska region with the cold climate of continental Slovenia, there are frequent winds, long-lasting snowfall, as well as sleet, which the trees have adapted to with their growth.