Its colours are reminiscent of tropical seas, its bends offer unforgettable glimpses capable of sending the imagination to distant places, cradled by a gentle current and the gurgling of moving water. Yet the Tirino lies in the heart of Italy, within the Gran Sasso e Monti della Laga National Park at almost 400 metres above sea level.

It rises in an unspoilt corner of the municipality of Capestrano, in the province of L'Aquila, and offers a cool, lively oasis in an otherwise far more static landscape, where wide open spaces are surrounded by towering mountain massifs. It is precisely from these rocky peaks that the clear water that defines the Tirino filters through — the quality that has earned it the title of Italy's clearest river.

A canoe trip along the river, the undisputed star of its valley, is therefore not to be missed on a warm summer's day. It is organised by the guides of the cooperativa il Bosso, an environmental education centre based right near the source.

The magic of this river is not immediately obvious — you have to step up to the bank to discover its enchantment.

The approach is short, the preparation straightforward, and the canoes are stable and safe. The river's current is calm and instils a sense of tranquillity. But it is the colours that inexorably invite explorers to let their craft glide onto the water, finding themselves suddenly suspended over an unreal turquoise.

This is the key to understanding what makes the Tirino unique.

Its waters travel a long underground stretch before filtering through the rocks of the Gran Sasso-Sirente massif and emerging into the light: they pass from the subsoil into the river through countless micro-springs, known as polle d'acqua, whose presence is betrayed by tiny bubbles. This constant recirculation of water prevents vegetation from taking hold across much of the white rock riverbed, causing the colours to burst forth with particular brilliance. Elsewhere, aquatic plants are able to colonise the bed, and the transparent water allows them to receive sunlight.

Throughout the excursion, the guides' thorough explanations reveal the soul of a cooperative whose aim is to educate visitors, foster ecological awareness and disseminate scientific knowledge. They stop to observe the flora and fauna, to explain the behaviour of water birds such as the little grebe and the coot — skilled swimmers that live along the river — or to let visitors taste sedanina, a plant that lives underwater and plays an important role in supplying the river with oxygen. They recount that there is a population of small native crayfish, Austropotamobius pallipes, and that the only fish living in the river are trout — the native species being the brown trout: lovers of cold, oxygen-rich water, they are an indicator of the river's water quality.

Halfway along the route, having reached a quiet bend where the ecosystem will not be disturbed, under the watchful eye of the guides the more daring visitors try to ease themselves into the water, following strict rules laid down by the protected area. It takes courage, however, to swim in water that has a constant temperature of 11 degrees Celsius all year round, a direct consequence of its underground origins. A rush of adrenaline and a jolt of vitality, before turning back and returning to the starting point, carried gently along by the current.

The sustainable development of the river Tirino and its valley

The cooperativa il Bosso was the first to operate in this area, already 20 years ago, and today holds the exclusive concession to bring its sit-on-top kayaks to this stretch of river. Paolo Setta, the facility's tourism manager, tells us how this adventure came about. "When we started this activity there was nothing here: we saw a potential built on tourism and we invested in it," he says. "Twenty years on, we can say our vision has proved successful — we have pursued sustainable tourism combined with an essential objective of environmental education," he states, citing figures that confirm the soundness of the project.

Every year, il Bosso involves 30,000 visitors in its activities and employs around 70 people during the summer period, while 12 people make up the permanent staff. The cooperative sustains itself through tourism and educational activities for adults and children, as well as professional training and activities with schools. For educational purposes it also organises trekking linked to the grape harvest among the vineyards of the Tirino valley, or excursions to the wolf visitor centre in Popoli.

The cooperative's success also rests on the development of the surrounding area, which involves local producers. For example, the agri-ristoro located within the excursion centre serves zero-kilometre products: vegetables from the neighbouring farmer, wine from the vintner on the adjacent hillside, cheese from the cheesemaker at the end of the road, while local farmers continue to honour tradition by also cultivating an ancient grain such as solina, a native variety of soft wheat typical of the mountain municipalities of the province of L'Aquila and a Slow Food Presidium. In this way, the cooperative's work also brings value to the surrounding communities. "Over time, our intuition has been followed by other operators who, however," Setta laments, "do not always have sustainability and the shared generation of wealth at heart — something that only those with deep roots in the territory can truly demonstrate."

Beyond the river: itineraries in the Tirino valley

In these places nature takes centre stage, the pace is slow, the spaces are wide and the valleys expansive. Visiting and admiring these varied beauties requires a different kind of time — the time of ascent and descent, of learning and observation. As so often happens away from the most well-trodden routes, the inland and mountain areas are not crowded with tourists, yet they are nonetheless dotted with small gems especially dear to the people of Abruzzo.

From Rocca Calascio, a ruined castle full of charm, to the village of Santo Stefano di Sessanio, once a crossroads of the wool trade and today restored as an albergo diffuso, to that of Navelli, which overlooks the plain of the same name, famous for "red gold" — the saffron that yields wonderful blooms.

Around the Tirino valley an "eco-itinerary" has also been developed, a route that ideally follows the water that springs from the mountains surrounding and towering over these lands. Developed with funding from the European Interreg emblematic mountains project, which involves 9 mountains across Europe, the route aims to promote certain Mediterranean mountains, with their specific characteristics and features.

There is another curious activity centred around the river. The main source of the Tirino now feeds into the artificial Capodacqua lake of the same name, created last century to irrigate the surrounding fields and more recently also used as a reservoir for the generation of electricity. Swimming freely in the lake is not permitted, but a diving centre organises dives to see — aided by the crystal-clear water — the ancient mills that were submerged when the lake was created, a testament to a past in which this area was home to industries and dye works, with the Tirino as their water-powered engine.

The area has much to offer, especially for those who love the mountains and the simple, heartfelt hospitality typical of the Abruzzesi, who are themselves deeply in love with their land. "This is an amusement park, in winter and in summer alike," Alessandro tells me — a young man from L'Aquila who ventures into his mountains whenever he can: when he is not out hiking, the ski lifts carry him to the summit on skis in winter, and in summer they transport his downhill mountain bike. "I live in the most beautiful place in the world."

One river, just a few kilometres to change character

Before tourism developed in this area, people lived mainly from farming and livestock rearing, but also from industry — in particular at Bussi sul Tirino, just 11 kilometres further downstream, where for half a century there has been an industrial hub with a power station, chemical plants and, as was unfortunately discovered, illegal dumps of hazardous waste that have contaminated the soil, the river and even the water supply network.

And so it is that the Tirino, which springs up clear and pure in an idyllic spot, ends up flowing into the river Pescara less than 20 kilometres further downstream in a heavily contaminated area.

Since 2008 the Bussi area has been declared a site of national interest (SIN) requiring remediation, yet in 12 years no clean-up has been carried out. Funds were in fact allocated, a project was drawn up and a contractor had been identified for the works, but in recent months the Ministry of the Environment cancelled the tender aimed at carrying out the remediation works. At this point, reopening the whole process would further delay the start of works, causing serious harm to the local community.

In the meantime, a ruling by the Council of State in June identified the company Edison S.p.A as responsible for the contamination in the area of the two hazardous waste dumps; it must therefore carry out the remediation works and bear the costs, in accordance with the "polluter pays" principle. The environmental conflict has yet to be resolved.