Mera river-Fraga dos Casás

In the surroundings of the area known as Fraga dos Casás there are several outcrops of black and greenish rocks, especially in the mountains known as Coto da Pena, Coto do Covelo, A Casanova and O Ermo. All of them are taken as the remains of an ancient ocean – the Rheic Ocean – which existed more than 400 million years ago and which later, around 350 million years ago, disappeared as a consequence of the great collision between Laurussia and Gondwana, the two primitive continents that would eventually become part of the supercontinent Pangaea. The valley of the river Mera – originated in the last million years of our planet’s history – is undoubtedly the most visible morphological element in the landscape. It is very steep because the source of the river is very close to its mouth and, as a result, it has to overcome almost 700 metres of unevenness in just over 20 kilometres.

City councils: Cerdido and Ortigueira
Can I visit it?: Yes, by car or on foot as a walking route.
Further information: We recommend to visit with a specialist guide to identify the geological resources – except for the river valley itself, which flows into Ponte Mera.

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© Mancomunidade de Concellos da Comarca de Ferrol

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