Tourists often assume that Portugal’s nature is limited to ocean landscapes. Even many locals are unaware of its hidden natural wonders. Today we’ll show you where and how to discover true natural landmarks around Caldas da Rainha.
Nascentes
A nascente is a fascinating natural phenomenon, meaning a “spring” or the “birth” of a river. In Portugal, especially in the mountain range of Serra de Aire e Candeeiros, a nascente is a place where rivers quite literally emerge from underground, as if from nowhere. These springs are not just droplets of water — they mark the beginning of entire underground rivers flowing through labyrinths of caves and tunnels.
The main mechanism behind a nascente is tied to natural rainfall. Rainwater seeps through the porous limestone of Serra de Aire e Candeeiros, slowly filtering down and collecting in underground reservoirs and channels. These subterranean flows, sometimes stretching for dozens of kilometers, move beneath the surface and help maintain the region’s water balance.
When an underground river reaches the surface through cracks or cave openings, it is born as a nascente — a clean and clear spring that becomes the beginning of a surface river. This process is part of a complex hydrogeological system, unique to karst landscapes like Serra de Aire e Candeeiros.
We recommend visiting Nascente do rio Lis, Nascente do rio Alviela, and Nascente do rio Almonda — all visually stunning locations. As for Nascente do rio Lena, it takes a bit more effort to find, as it discreetly emerges among bushes and requires close attention. However, the walk to any nascente is always scenic and rewarding.
Fontes
In Portugal, sources of clean drinking water, known as fontes, are an important part of both nature and culture. Water in these springs is formed when rainwater seeps through layers of rock, is naturally filtered, and accumulates in underground reservoirs. From there, it emerges at the surface, forming springs with fresh, clean water.
These types of sources are commonly found in karst regions with limestone formations, where water flows through underground tunnels, getting purified and enriched with minerals. However, not all fontes turn into full rivers — many are simply equipped as fountains with taps, making it easy to collect drinking water.
One example of such a drinking water source is Fonte da Senhora near the town of Benedita. Free, clean, drinkable water in unlimited quantities — a great alternative to bottled water from the supermarket.
Pay attention to the signs near a fonte. Very old fontes may not guarantee water quality, simply because there is no regular control. However, it is always clearly marked if the water is not suitable for consumption.
Lagos em cavas de extração
Lakes formed in abandoned sand quarries are unexpected gems of the landscape. After sand extraction ends, the machinery is removed, and the quarry is left open. Over time, rainwater begins to fill these depressions, creating lakes with a striking blue color. This hue appears thanks to the light-colored sandy walls and bottom, which reflect sunlight, and also due to the purity of the water, untouched by muddy streams or wastewater.
Although swimming in these lakes is often officially discouraged, this is more a precaution than a real danger. Authorities usually don’t carry out regular water quality checks, so warning signs are posted. However, frogs and aquatic insects can often be found in these lakes — a clear sign that the water is not toxic and supports life.
For those who prefer not to take risks, simply enjoying the views is well worth it. These lakes have an unusual, almost alien beauty: vivid blue surfaces surrounded by sandy slopes, as if taken from a science fiction landscape. They are especially stunning against a backdrop of green hills or under clear skies.
One example is Lago Azul, located near the village of Campo. It’s a typical case of a quarry that nature has transformed into a true natural wonder. The water here is exceptionally clear, and the scenery feels like something from another planet.
Places like this are a perfect excuse to step off the usual tourist paths and discover a new side of Portugal — unexpected, wild, and incredibly beautiful.
Barragens
Barragens are important hydraulic structures built to store water, regulate rivers, and supply surrounding areas. Behind almost every barragem lies a large artificial lake — a reservoir that impresses with its scale and tranquility.
These places are often far from tourist routes, making them perfect for those seeking peace, silence, and a deeper connection with nature. Here, you can go boating or paddleboarding, have a picnic, or enjoy fishing. Many of these reservoirs are surrounded by forests or hills, creating a feeling of total escape from the rush of everyday life.
Despite the calm and clean water, you’ll often see signs forbidding swimming. However, this is usually a precautionary measure. Swimming isn’t prohibited due to pollution or real danger, but because there are no lifeguards, and local authorities prefer not to assume responsibility in case of an accident.
Still, simply sitting by the water, listening to the wind and birdsong, can be deeply satisfying. Many barragens in Portugal remain relatively unknown, even to locals, which helps preserve their untouched and natural charm. They’re ideal for slow-paced relaxation, reflection, and a genuine encounter with the Portuguese countryside.
As examples, we recommend visiting Barragem de Alvorninha, Barragem do Rio Arnóia, and Barragem da Atouguia da Baleia — all serene and beautiful locations well worth discovering.
Praias fluviais
In addition to the famous Atlantic beaches, Portugal is home to many praias fluviais — river beaches that offer a great alternative for those who want to relax by the water without traveling far or spending an hour driving to the coast.
River beaches can be found in nearly every region of the country, especially in the central and northern parts. They’re located along rivers and streams, where the water is clean, flowing, and usually cooler than in the ocean — a refreshing escape on hot summer days. Many of these spots are equipped with swimming areas, wooden decks, restrooms, cafés, and even lifeguards during peak season. Some have earned the “Blue Flag” for water quality and facilities.
Praias fluviais are perfect for family outings, picnics, or simply a peaceful day in nature. Without the large waves of the ocean, swimming is calmer and often safer. The surrounding scenery — forests, cliffs, hills — creates a picturesque and peaceful atmosphere.
The most scenic river beach accessible from Caldas da Rainha is Praia fluvial dos Olhos de Água. There, you can enjoy both the nascente and the praia fluvial in one visit.
Conclusion
No one — whether a tourist, expat, or local — will regret visiting these places. They remain largely unknown to the public, hidden from mass tourism, and that’s exactly what makes them so special. These natural corners inspire, broaden your perspective, and show you a different Portugal — not just through the ocean and beaches, but through quiet mountains, cool riverbanks, blue quarry lakes, and the serenity of barragens. Visiting these spots enriches your personal experience and makes a wonderful addition to your learning journey with our school. Most importantly, it lets you feel the real Portugal — the one guidebooks rarely reveal.