The Soča valley by bike: Bovec to Tolmin along the emerald river

The Soča runs 138 km from a karst spring in the Trenta valley to the Adriatic, and for the first part of that — from Bovec at 452 m down through Kobarid to Tolmin — it is followed by a road that is one of the most pleasant pieces of intermediate cycling in the Alps. The river is the colour it is in the photographs. The valley road is not the whole story, though. What makes the Soča a place to spend a week rather than a day is the climbs that leave it: a First World War ridge, a village on a shelf, and two passes into Italy. Here is how the valley fits together, with distances from the regional tourist board rather than from memory.

The valley road: Bovec to Tolmin

The spine of the region is the road along the river. From Bovec it drops past the Boka waterfall, through Žaga and Trnovo to Kobarid, then on along the Soča to Tolmin, the largest town in the valley and its administrative centre. It is a gentle descent southbound and a gentle climb northbound, with the river beside you almost all the way. The regional tourist board's Emerald Cycling Trails guide describes the stretch as running "practically on flat" apart from a few short sections, and grades its Cividale–Tolmin route through Kobarid at 45 km with only 350 m of climbing.

Two honest caveats. It is the main road, and in July and August it carries the rafting and kayaking traffic — minibuses with trailers, mostly, driven by people who know the road well and drive it accordingly. And the stretch through the gorges above Kobarid is narrow. Ride it early in the day in summer and it is lovely; ride it at four in the afternoon in August and you will spend the time looking in your mirror.

The tourist board runs a network of summer shuttles between Tolmin and Bovec, and to Javorca, from late June to the end of August with reduced weekend services in September, and a year-round bus over the Predel pass. If you want a one-way day, that is how to do it.

Kobarid, and the Kolovrat ridge

Kobarid sits beneath the Krn range, which tops out at 2,244 m, and it is the centre of the valley's First World War history: the front ran along this river for two and a half years, and the Kobarid Museum, which has won the Council of Europe Museum Prize, tells that story better than anywhere else. Just outside the town the Napoleon Bridge — the single stone arch was built in 1750 and named after the troops who crossed it on their way to Predel — spans the Soča gorge. Both are worth the stop.

The ride that matters from Kobarid is Kolovrat. The ridge rises steeply from the right bank of the river between Kobarid and Tolmin, and along its crest the Italian army built its third line of defence, part of which is now an open-air museum of trenches, observation posts and gun positions. The road goes through Idrsko to Livek (5 km), left towards Livške Ravne (4 km) and a further 3 km along the ridge to the museum's small car park; the initial climb is about 800 m in the guide's description. The board's full Kolovrat tour is 48 km with 1,360 m of climbing, dropping off the far end of the ridge into the Goriška brda wine country before returning. From the top you can see the Julian Alps, the Friulian plain and, on a clear day, the sea. It is the best climb in the valley that nobody outside Slovenia has heard of.

Drežnica, Javorca and the Tolmin side

The tourist board's Juliana Bike stage from Bovec to Tolmin is 49.3 km with 1,763 m of climbing, which tells you how much height there is off the valley floor once you leave the river. That stage climbs to Drežnica, the village on a shelf beneath Krn, and continues past the pastures below the mountain into the Tolminka valley, where the Church of the Holy Spirit at Javorca and the Tolmin gorge are the two sights worth the detour. The road to Javorca is a dead end and quiet; the Drežnica climb from Kobarid is short, steep and the best mid-ride view in the valley.

South of Tolmin the valley widens. Most na Soči has the emerald lake you can row on, and from there the board's Tolmin–Nova Gorica route (42.5 km, 600 m) runs on down towards the Vipava valley and the Karst — which is, for anyone doing a longer tour, the way out of the mountains to the Karst and the coast.

Bovec, Predel and the big loop

Bovec is the top of the valley and the base for the two high roads: Vršič to the north-east, via Trenta, and Mangart off the Predel road to the north. Both are covered separately. The board's own big day from Bovec is the loop around Kanin: 96 km and 1,800 m through Čezsoča, over the Predel pass into Italy, round to Sella Nevea and back through the Resia valley — a tour the guide says "presents a challenge even for well-prepared cyclists", which is fair. It can be split over two days.

If you only want one climb from Bovec that is not a pass, the road up the Koritnica valley to Log pod Mangartom and on to the Predel junction is steady, wooded and, according to the board's Juliana Trail notes, finishes with a steep 500 m rise to the pass itself.

The rain, and how to plan round it

The reason the valley is this green is that it is the wettest lowland place in Slovenia. ARSO's 1981–2010 normals for Bovec give 2,602 mm a year, with more than 320 mm in each of October and November and the driest month, July, still at 187 mm. Summer thunderstorms build over the mountains in the afternoon with little warning. The July mean daily maximum is 26.0 °C, so it is warm rather than hot, and the limestone gets slippery the moment it is wet.

This does not make it a bad place to ride. It makes it a place where the day has a shape: climbs in the morning, valley in the afternoon, and a jacket in the pocket regardless of the forecast. If you are putting a week together, planning a cycling trip covers keeping a wet-weather alternative, and here the alternative is always the valley road, which is ridable in almost anything.

The rules in the national park

Much of the upper valley, including Trenta and the slopes above Bovec, is inside Triglav National Park. The park's rules for bikes are simple and worth knowing: cycling is allowed on existing roads built for motor traffic and on forest roads, in daylight, and is forbidden in the natural environment off them. For a road cyclist that changes nothing; for anyone tempted by a gravel shortcut across a pasture it does. The Juliana Bike route is the park's own coordinated long-distance line and stays on permitted roads throughout.

A week, roughly

• Day 1. Valley road Bovec–Kobarid–Tolmin and back, or one way with the shuttle. Flat, and the way to learn the road.
• Day 2. Kolovrat from Kobarid, 48 km, 1,360 m.
• Day 3. Easy: Tolmin to Most na Soči and Javorca. Coffee in Kobarid.
• Day 4. Vršič from the Trenta side, or the Kanin loop over Predel.
• Day 5. Recovery on the valley road, or nothing.
• Day 6. Mangart, early, if the road is open.

Base in Bovec for the high roads or Kobarid for everything else; Tolmin is the practical choice if you want the biggest town and the shortest ride to Most na Soči. Any of the routes above can be saved in Moveee and ridden in Moveee Indoor when the valley is under 300 mm of November rain, which is the one month we would not send you there.