Covão dos Conchos

It might sound unusual that someone would hike for an hour to see a drain-pipe. But perhaps, after you have seen photos of this particular feat of engineering, you will want to visit it yourself. That was the reaction that I had after seeing images online. Whilst it may just be a large funnel-shaped drain, it is surprisingly beautiful and is certainly unusual. It gives the impression of a mystical portal to the centre of the Earth.


Covão dos Conchos is a small lagoon located in the Serra da Estrela mountain range. In 1955, in order to drain water from this lagoon to the larger Lagoa Comprida (a dammed reservoir), a 1519 meter tunnel was constructed. In one corner of Covão dos Conchos, this tunnel has a funnel-shaped opening. When the water levels rise above the lip of this funnel, the water drains through the tunnel to Lagoa Comprida. The tunnel has a longer sister, that runs 2354 meters between Lagoa Comprida and Covão dos Meio, but I haven’t been able to find any reference to a similar funnel-drain for that one.


Lagoa Comprida is the largest reservoir of the Estrela region and, in addition to supplying water to the area, it is also a source of hydro-electric power. The first Lagoa Comprida Dam was constructed in 1912, when it was the first such engineering project in Portugal. At that time, the dam was only 6 meters high. The dam was enlarged in 1934 and 1966 and now measures 28 meters high, 2,500 meters long and 130 meters wide. The dam is built from granite that was quarried from a nearby location.

Lagoa Comprida Dam, with the reservoir on the left and the car-park on the right

Lagoa Comprida is an attraction itself, with many families heading there to spend the day on its shoreline, swimming, picnicking and sun-bathing. It has a car-park located adjacent to the road as well as a small shop selling regional products and a bar. The car-park is also the starting point for a hike to Covão dos Conchos.


Those wishing to visit Covão dos Conchos will need to hike from the car-park next to Lagoa Comprida. It is an easy route, the majority of which is on a dirt road the width of a car. Whilst the road could be ridden with a dirt-bike, there are a couple of very rocky stretches.

The dirt road starts from the left of the shop and bar, when facing them from the car-park. The trail is 2.8 miles long (4.5km) with elevation changes from 5,225 to 5,577 feet (1,592 to 1,700 meters). There are no sign-posts along the road, so just stay on the main path. There is a Y-junction along the way – stay left on the rocky footpath and you’ll be fine. It took me about one hour to get to Covão dos Conchos, stopping along the way to take photos. The return leg only took me 45 minutes. But I do walk fast! I’ve seen other reports suggesting that the hike can take between 75 – 90 minutes for those who don’t walk so fast. Below is an image from my Wikiloc trail, showing both legs of the hike. If you wish, you can download the gpx file for the hiking route from this link.

Screen Shot 2018-08-21 at 6.19.04 PM



The hike to Covão dos Conchos is very pleasant. During the first segment, there are occasional views of Lagoa Comprida and then open areas of rocky habitat with lots of heather and gorse plants. Whilst there are some inclines and declines, they are not very strenuous, so the route is suitable for most levels of walkers and even children. Mostly it is dirt road with a few rocky sections to deal with.


Covão dos Conchos is at the end of the 2.8 miles track, but the star attraction is not immediately visible. In order to see the drain, you need to walk half-way around the lake, counter-clockwise. There is a meter-wide walkway on top of a concrete dam. After walking across that dam, and over some large boulders, there is a much narrower concrete dam. You can either ‘tightrope walk’ across the narrow dam or you can take the easier dirt path to the opposite end of it. From there, walk up and over more boulders and the drain will come into view. And it’s a beautiful sight!


After you have walked back along the trail, don’t forget to stop in at the little shop next to the car-park. They have some nice regional produce for sale, including locally produced chourico, the strongly flavoured Estrela sheeps cheese and a rather nice blueberry liqueur, as well as honey and other items.



Unfortunately, at the time of my visit, the water levels in Covão dos Conchos were not high enough to see water cascading down the drain. We haven’t had rain in Portugal for a few weeks. But, to get an idea of what the place looks like in winter or when the water is draining, here is a link to someone else’s YouTube video. Well worth a look.

Getting There

Lagoa Comprida is about 181km from Porto, which equates to a 2.5 hour drive. The A1 and A25 motorways will allow you to quickly cover a large chunk of the journey. After that, pick up the N231 towards Seia. From Seia, the N339 will take you through Sabugueiro and up the mountain. You’ll pass Covão do Curral on your right and then, a bit further up the mountain, you’ll see the Lagoa Comprida Dam on your left. You’ll have to pay tolls on the motorways (including electronic-only tolls on the A25) but it is the quickest way to get there. Once you are on the N-roads, the driving becomes more enjoyable.

If you are thinking about visiting in the winter, be aware that this is the highest mountain range in Portugal and that it does get snow (note the snow depth indicator poles in some of the photos below).


1 Comment

Leave a Reply

Fill in your details below or click an icon to log in: Logo

You are commenting using your account. Log Out /  Change )

Google photo

You are commenting using your Google account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s