Croagh Patrick, Sacred mountain in County Mayo, Ireland.

Croagh Patrick is a quartzite mountain in County Mayo that rises 764 meters above sea level in a pyramid shape overlooking Clew Bay. The summit holds a small white chapel visible from the coast on clear days.

Tírechán wrote in the 7th century that Saint Patrick spent forty days fasting on the mountain, like Moses on Sinai. Archaeologists found a stone chapel or oratory on the summit dating from the 5th century, and a "Teampall Phádraig" is recorded in AD 824. The small modern chapel was dedicated on 20 July 1905.

On the last Sunday of July, thousands of pilgrims walk to the summit, many choosing to climb barefoot over sharp stones and loose scree. A small chapel at the top holds Mass on that day, with people forming long queues outside as they wait their turn.

The climb takes between two and three hours depending on pace and weather conditions, with the upper section crossing loose scree. The visitor center in Murrisk at the foot of the mountain offers information, toilets, and parking.

The Boheh Stone, a rock outcrop east of the mountain, carries more than 260 prehistoric carvings, one of only two such sites in Connacht. In 1987 it was noticed that from this stone the setting sun appears to roll down the slope of Croagh Patrick in late April and late August, which is thought to explain why the stone was chosen.