“Earth and sky, woods and fields, lakes and rivers, the mountain and the sea, are excellent schoolmasters, and teach some of us more than we can ever learn from books.” John Lubbrock
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Errigal (An Earagail) is a 751-metre (2,464 ft) mountain near Glenveagh National Park in County Donegal, Ireland. It is the tallest peak of the Derryveagh Mountains and the tallest peak in County Donegal. Errigal is also the most southern and the highest of the mountain chain called the “Seven Sisters” by locals.
This mountain chain contains some of the oldest rocks in Ireland. They are metasedimentary rocks of the Lower Dalradian age (700-600 million years ago). Around 470-450 million years ago, tectonic plate collisions produced high temperatures and high pressures and converted mudstone to schists, and sandstone to quartzites.
