Roadbook S1 Half Trail — the course, trail by trail

The S1 Half Trail starts at PortoPiccolo and returns there after 23.3 km, with Monte Ermada at the heart of the course. This page describes the course in the order you come to it: the CAI trails, the routes that run alongside it for a stretch and the race’s own connecting sections.

From PortoPiccolo to the Sentiero Rilke

From the Bora Village at PortoPiccolo the S1 Half Trail gets off to a fast start. The start is at ‘Le botteghe’, inside PortoPiccolo, and the course drops down Strada della baia and Strada di PortoPiccolo to Sistiana Bay; from the bay a flight of stairs climbs up to the road, and the S.P. 3, on tarmac, leads to Piazza Barone Goffredo de Banfield, where the course joins the Sentiero Rilke. It is about 2.1 km, almost all on road: the field has time to spread out before reaching the trail.

From here the course follows CAI 001, partly shared with the Alpe Adria Trail and, along the cliffs, with the Sentiero Rilke. These are separate routes that happen to run on the same ground here: sharing a stretch does not make them the same thing.

The Sentiero Rilke runs for just over two kilometres, suspended between sky and sea, along the Duino Cliffs Nature Reserve, between Sistiana/Sesljan and Duino/Devin. It was here, in the winter of 1912, that Rainer Maria Rilke — a guest of Princess Marie von Thurn und Taxis at Duino Castle — heard the first words of the Duino Elegies carried to him on the wind: ‘Who, if I cried out, would hear me among the hierarchies of angels?’ It is from these cliffs, too, that the Corsa della Bora takes its motto: ‘Being here is glorious’.

Duino and the Sentiero del Mitreo

The course follows the Sentiero Rilke as far as Duino/Devin and passes through the old village in front of Duino Castle, the residence of the princes of Thurn und Taxis, where, according to tradition, Dante was a guest before Rilke; beside the ruins of the old castle you can make out the White Lady, the rock shaped like a veiled woman.

From Duino the course picks up CAI 001a — Sentiero del Mitreo. At the Mithraeum Cave, also known as the Duino Mithraeum, it leaves CAI 001a for CAI 033. Shortly afterwards comes the second point where the races split: the S1 Family Hike & Trail turns off onto its own shorter loop, while the S1 Half Trail, S1 Borderless Trail, S1 TransKarst Ultra and S1 Bora Ultra carry on along CAI 033.

Towards Medeazza

Beyond Duino the terrain changes character: you leave the coastal cliffs behind and head into the heart of the plateau, where Monte Ermada — Grmada in Slovene, 323 metres — dominates the landscape like a sentinel between two worlds. The climb is gentle and steady, never brutal, through mixed woods of pine and beech; its slopes still hide trenches and fortifications from the Great War, now reclaimed by vegetation.

The S1 Half Trail carries on along CAI 033 and then moves to CAI 003a, which leads to Medeazza/Medjavas. Here, at around km 10.4, comes the main split between the races: the S1 TransKarst Ultra and the S1 Bora Ultra take the long branch towards Jamiano, while the S1 Half Trail continues together with the S1 Borderless Trail towards Monte Ermada.

The cross-border sector of Monte Ermada

From Medeazza the course picks up CAI 003 — Alta Via del Carso — and runs through the cross-border sector of Monte Ermada/Grmada, past the area around the Jastreb summit, the Grofova jama (Grotta del Fuoco, also known as Vogenca) and the Grotta 1ª a nord del Monte Querceto.

This is one of the Karst landscapes most densely marked by the war. After the Sixth Battle of the Isonzo, in 1916, the Austro-Hungarians, having fallen back from the heights of Monfalcone, made Ermada the linchpin of their defences, controlling the Brestovizza valley and the routes towards Trieste. Today the mountain is an open-air museum — trenches, cave shelters, artillery emplacements and observation posts — and a stop on the Walk of Peace/Pot miru, the cross-border remembrance trail linking more than three hundred First World War sites across Italy and Slovenia, from the Alps to the Adriatic; the Walk of Peace documents the mountain’s positions and hiking loops. The Grofova jama is a cave rich in formations, where Austro-Hungarian engineers carved out terraces and bunks for the troops.

The Grotta del Motore and the fork with the S1 Borderless Trail

The course continues on CAI 003 to the Grotta del Motore, also known as the Caverna del Monte Querceto: a natural cave adapted for military use. Here, at around km 13.5, comes the fork with the S1 Borderless Trail, which carries on eastwards on CAI 003.

The S1 Half Trail, by contrast, leaves CAI 003, follows a forest track and briefly takes CAI 008, where it overlaps with the Vertikala SPDT. Without dropping down towards Ceroglie, it reaches the summit and fore-summit area of Monte Ermada and passes close to the Grotta sul Monte Ermada.

The return: Case Coisce, Visogliano and PortoPiccolo

From the summit area the course continues on CAI 003a through Case Coisce/Kohišče, then takes CAI 033 and rejoins the S1 Family Hike & Trail shortly before the stretch that passes close to the Grotta Alexander.

From here the two races run together towards the Visogliano/Vižovlje sports ground, pass through Villaggio Verde Tre, drop down to Sistiana and return to PortoPiccolo. The last kilometres are the most runnable descent on the course: the route heads back towards the sea and closes the loop at the Bora Village.

Technical sequence

PortoPiccolo roads, stairs and S.P. 3 → CAI 001 / Sentiero Rilke → CAI 001a → CAI 033 → CAI 003a → CAI 003 → forest track → short stretch on CAI 008 / Vertikala SPDT → CAI 003a → CAI 033 → stretch shared with the S1 Family Hike & Trail → PortoPiccolo

The race forks

The distances starting from PortoPiccolo split at precise points, checked against the official 2027 tracks.

• S1 TransKarst Ultra / S1 Half Trail, S1 Borderless Trail and S1 Family Hike & Trail — split at the start, at around km 1.2: the S1 TransKarst Ultra climbs via the old start route, while the others head down to Sistiana Bay; the tracks come together again at around km 3.0 of the S1 Half Trail.
• S1 Family Hike & Trail / S1 Half Trail — split shortly after the Mithraeum, at around km 8.05; the two tracks meet again at about km 8.66 of the S1 Family Hike & Trail, which corresponds to about km 17.22 of the S1 Half Trail.
• S1 TransKarst Ultra and S1 Bora Ultra / S1 Half Trail and S1 Borderless Trail — split at Medeazza, at around km 10.4 of the S1 Half Trail and km 10.2 of the S1 Borderless Trail.
• S1 Half Trail / S1 Borderless Trail — split at the Grotta del Motore, at around km 13.5 of the S1 Half Trail and km 13.3 of the S1 Borderless Trail.
• S1 Borderless Trail / S1 TransKarst Ultra and S1 Bora Ultra — they merge again just after Monte Sambuco, at about km 15.9 of the S1 Borderless Trail and about km 34.8 of the S1 TransKarst Ultra.

Further reading

• Official list, routes and technical data sheets for the trails: CAI FVG trail register — Sector 0 Karst.
• The CAI trails of the Karst — trail numbers, official names and the 2027 races across the whole network.
• The open-air museum of Monte Ermada/Grmada, a stop on the Walk of Peace/Pot miru, and the description of the Grofova jama by CAI Gorizia.
• Duino and the Sentiero Rilke, The Bora, the wind and PortoPiccolo and Sistiana Bay.
• Trail running in Trieste and on the Karst — the same trails, open all year round.

This description is editorial and is meant to help you understand how the course is put together, trail by trail. When it comes to actually following the route on the ground, whether in training or in the race, the official track and the course markings put out by the organisers are what count. Up-to-date distances, elevation gain, time barriers and refreshment points are published on the race page, S1 Half Trail 23 km; the trail network that all the Corsa della Bora courses are built on is described on the page The CAI trails of the Karst.