Source Kova dos Konćos on the mountain chiers de Estrela in Portugal for more than 60 years of astonishing, but also fascinated by their appearance. Looks like a gateway to the world below the surface. Although it has the appearance of a door leading into another world, one should say that he was not a miracle of nature, it is related to human activities and influence. The Kovado dos Konćos part of a hydroelectric power plant, built back in 1955 and actually serves to “suction” of water from the lake to the dam Lagoa Komprida. Although it was not created by nature, that is no reason not to be admired. It realized numerous tourists hikers, who despite the difficult path that leads to it, do not give up their intentions to see it.