If you just thought that you have seen all the best places on Earth, then think again. This water tunnel in Portugal is the most fascinating thing you would’ve ever seen. Part of the Covao dos conchos, a man-made dam located on top of Portugal’s highest mountain range – Serra de estrela.
What can look like an opening into another dimension is actually a dam which collects water from Ribeira das Naves.
The tunnel that collects the water is 1519 meters long with a circumference of 48 meters. This hydroelectric system was constructed in 1955.
So be sure to behold this sight on your next trip to Portugal. But remember that this sight is only visible for a short time, meaning only available during the rainy season as the water flows only during flood periods.
So let your imagination wild with this aerial video: