Glendalough (or "the glen of the two lakes") is one of Ireland's earliest and most important religious sites. It was founded by St. Kevin in the 6th Century, and over the following centuries developed into a "monastic city". It grew in status and wealth until the arrival of the Normans in Ireland. In 1214AD, the dioceses of Glendalough and Dublin were united, and Glendalough slowly diminished in status. Some sources describe the physical destruction of the site by the Normans at this time, but I've been unable to verify this. It does seem that the religious settlement effectively ceased to exist when it was sacked in 1398AD by English forces.
Like many Irish sites, the exact time-line of events at Glendalough is poorly documented. What can be said with certainty however is that the remains of the monastic buildings that can be seen today mostly date from the 11-12th Centuries, suggesting that this period was the time when Glendalough's wealth and status were at their peak.
The site is dominated by an impressive round tower, approximately 30 metres in height. The purpose of round towers has been disputed, but it is believed that they served as bell towers, storage space, and also as a refuge during an attack.
The cathedral is the largest of the surviving ruins at Glendalough. The chancel and sacristy have been dated to the early 13th Century. Although the building is only a shell, the remains of the chancel arch are still visible. A few metres south of the cathedral is a granite cross commonly known as St. Kevin’s Cross.
Other buildings include the priest's house, St. Kevin's Church (a beautiful little building with a slate roof and small round tower), St Mary’s Church and the gateway - Ireland's only surviving example of a medieval gateway to a monastic site.
Today, Glendalough is one of Ireland's premier tourist attractions. However, the visitor centre is unobtrusive, and the ruins can be explored without any intrusion from the modern world. It's a busy site, but the setting is absolutely stunning, and it's hard not to be overwhelmed by the magic of the surrounding landscape.