Glendalough, meaning Glen of Two Lakes is a glacial valley. Originally there was one lake but the Pollanas river, via Pollanas waterfall created a delta which split the lake in two. The valley is also home to former mining villages, between 1825 and 1925 50,000 tonnes of lead and 25,000 ounces of silver were mined here. Today Glendalough is popular for it's hiking trails and rock climbing.

St. Kevin founded a monastery at Gledalough in the 6th century, the original timber structures are long gone but many of the later stone constructions built between the 10^th and 12^th centuries remain. The buildings included a round tower, a cathedral, several churches and a priest's hoouse where priests were laid out before burial. The carving on the crosses in the graveyard are intricate and typical of Celtic crosses. One possible reason for this intricate carving is that it was more sensible to carve this artwork into stone rather than precious metals which could be the subject of plundering from vikings. The monastery at Glendalough was raided by vikings in 1176 and also by the British in 1398.

"It was said that once a blackbird landed on St. Kevin's hand and treated it as a nest, laying an egg there. St. Kevin never closed nor withdrew his hand until the bird was fully hatched. Representations of St. Kevin usually include a blackbird sitting on his hand."