Roadbook S1 Half Trail — the route trail by trail

The S1 Half Trail starts at PortoPiccolo and returns there after 23 km, with Monte Ermada at the centre of the course. This page describes the route in the order you meet it: the CAI trails, the itineraries that run alongside it for a stretch and the race's own connecting links.

From PortoPiccolo to the Sentiero Rilke

From the Bora Village at PortoPiccolo the S1 Half Trail attacks the Karst edge straight away: limestone, Mediterranean scrub, the sea widening with every metre of ascent. It is not a gentle start, but an honest one — the Half tells you at once what it is made of.

From the Bay of Sistiana the course climbs towards the Sistiana quarry, crosses the wood above the bay and reaches CAI 001, partly shared with the Alpe Adria Trail and, in the cliff sector, with the Sentiero Rilke. They are independent itineraries running here on the same ground: a shared stretch does not make them the same thing.

The Sentiero Rilke is a little 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 by the wind: «Who, if I cried out, would hear me among the hierarchies of angels?». From these cliffs comes the motto of the Corsa della Bora, being here is glorious.

Duino and the Sentiero del Mitreo

The course follows the Rilke as far as Duino/Devin and crosses the old village in front of Duino Castle, the fifteenth-century residence of the princes of Thurn und Taxis where Dante was a guest before Rilke; beside the ruins of the old castle you can glimpse the White Lady, the rock shaped like a veiled woman.

From Duino the course takes CAI 001a — Sentiero del Mitreo. At the Mithraeum Cave, or Mithraeum of Duino, it leaves CAI 001a and takes CAI 033. Shortly afterwards comes the first race fork: the S1 Family Hike & Trail takes its own shorter loop, while the S1 Half Trail, S1 Borderless Trail, S1 TransKarst Ultra and S1 Bora Ultra continue on CAI 033.

Towards Medeazza

Beyond Duino, the terrain changes character: you leave the coastal cliffs and enter the heart of the plateau, where Mount Ermada – Grmada in Slovenian, 323 metres high – dominates the landscape like a sentinel between two worlds. The climb is gentle and continuous, never brutal, through mixed woods of pine and beech. Its slopes still hide trenches and fortifications from the Great War, now healed by greenery.

The S1 Half Trail continues on CAI 033 and then moves to CAI 003a, which leads to Medeazza/Medjavas. Here, at around km 9.8, comes the big race fork: the S1 TransKarst Ultra and the S1 Bora Ultra take the long branch towards Jamiano, while the S1 Half Trail continues with the S1 Borderless Trail towards Monte Ermada.

The cross-border sector of Monte Ermada

From Medeazza the course takes CAI 003 — Alta Via del Carso and crosses the cross-border sector of Monte Ermada/Grmada, passing through the area of the Jastreb summit, the Grofova jama — the Fire Cave, also known as Vogenca — and the Grotta 1ª a nord del Monte Querceto.

This is one of the densest war landscapes in the Karst. After the Sixth Battle of the Isonzo, in 1916, the Austro-Hungarians, having withdrawn from the heights above Monfalcone, made Ermada the defensive pivot 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 memorial itinerary linking over three hundred First World War sites between Italy and Slovenia, from the Alps to the Adriatic; the Walk of Peace documents its positions and hiking loops. The Grofova jama is a richly concretioned cavity where Austro-Hungarian engineers built terraces and sleeping places 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 Cavern of Monte Querceto: a natural cavity adapted for military use. Here, at around km 13.2, comes the fork with the S1 Borderless Trail, which carries on eastwards on CAI 003.

The S1 Half Trail, on the other hand, leaves CAI 003, follows a forest track and takes a short stretch of CAI 008, overlapping with the Vertikala SPDT. Without dropping towards Ceroglie, it reaches the summit and fore-summit sector of Monte Ermada and passes close to the Grotta sul Monte Ermada.

Back home: Case Coisce, Visogliano and PortoPiccolo

From the summit sector the course continues on CAI 003a through Case Coisce/Kohišče, then takes CAI 033 and merges again with the S1 Family Hike & Trail shortly before the stretch running close to the Grotta Alexander.

From here the two races run together towards the Visogliano/Vižovlje sports field, cross Villaggio Verde Tre, drop down to Sistiana and return to PortoPiccolo. The last kilometres are the most runnable descent of the course: the track heads back to the sea and closes the circle at the Bora Village.

Technical sequence

CAI 001 / Sentiero Rilke → CAI 001a → CAI 033 → CAI 003a → CAI 003 → forest track → short 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 share the opening kilometres and split at precise points, verified on the official 2027 tracks.

• S1 Family Hike & Trail / S1 Half Trail — split shortly after the Mithraeum, at around km 7.75; the two tracks meet again at about km 8.36 of the S1 Family Hike & Trail, which corresponds to about km 16.90 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 9.8 of the races starting from PortoPiccolo.
• S1 Half Trail / S1 Borderless Trail — split at the Grotta del Motore, at around km 13.2.
• S1 Borderless Trail / S1 TransKarst Ultra and S1 Bora Ultra — they merge again just after Monte Sambuco, at about km 15.6 of the S1 Borderless Trail and about km 34.8 of the S1 TransKarst Ultra.

Further reading

• Official list, tracks and technical sheets of the trails: CAI FVG trail register — Sector 0 Karst.
• The CAI trails of the Karst — numbers, official names and 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 Rilke Path, The Bora, the wind and PortoPiccolo and Sistiana Bay.
• Trail running in Trieste and the Karst — the same trails, walkable all year round.

This description has editorial value and helps you understand how the route is built trail by trail. To actually follow the track, in training as in the race, only the official GPS track and the race markings put in place by the organisers apply. Up-to-date distances, elevation gain, cut-off times and aid stations are published on the race page, S1 Half Trail 23 km; the network of trails on which every Corsa della Bora course is built is described on the page The CAI trails of the Karst.