Errigal, Mountain peak in County Donegal, Ireland.

Errigal is a quartzite mountain in County Donegal that rises prominently above the surrounding terrain. Its rocky cone-shaped profile is formed by hard white stone that stands out clearly against the landscape.

Errigal is the highest of the Seven Sisters, a chain of peaks that includes Muckish, Crocknalaragagh, Aghla Beg, Ardloughnabrackbaddy, Aghla More and Mackoght. Its name comes from the Old Irish airecal, meaning "oratory", though no remains of an oratory survive on the mountain. In legend the Fir Bolg, who came from Greece, named it after Mount Olympus.

The name comes from the Old Irish airecal, meaning "oratory", though no remains of one survive on the mountain. Legend credits the Fir Bolg, who came from Greece, with naming it after worshipping here as they had Mount Olympus. Locals call Errigal and its neighbours the "Seven Sisters".

The trail is well-marked and accessible for most visitors, though the terrain becomes rocky and steep as you climb higher. Weather conditions can change rapidly, so checking forecasts and bringing appropriate gear is important.

The white quartzite surface transforms in color throughout the day, glowing pink or orange during sunrise and sunset depending on light angles. Each viewing position reveals a completely different profile of the mountain.