The Outer Hebrides are a unique religious area in contemporary Scotland and Britain. The northern island (Lewis and Harris) is dominated by Calvinist 'free churches', and has been described as "the last bastion of Sabbath observance in the UK". It is also home to a unique form of Gaelic psalm singing known as precenting. The southern islands of South Uist and Barra are the last remnants of native pre-Reformation Scottish Catholicism. Barra was once dubbed "the island the Reformation did not reach". The Outer Hebrides are also home to some of Britain's most important pre-Christian religious sites. The most significant is the Callanish Stones on the isle of Lewis, which are notable megalithic sites dating back some 5000 years - older than Stonehenge. Catholicism in the Outer Hebrides Current status The 2011 Scottish Census found that unlike those in the Northern islands, the people of the southern islands were overwhelmingly Catholic. South Uist, the second most populated of the Outer Hebrides, was 90% Catholic, while Barra was 81.5% Catholic. The small islands of Eriskay (94%) and Vatersay (90%) were also heavily Catholic, while Benbecula, further north, was evenly divided between Catholics (55%) and Protestants (45%). Thus the southernmost of the Outer Hebrides are the most Catholic parts of all of Scotland. The two most Catholic civil parishes in the entire country are in the Outer Hebrides: History From the earliest period to the Reformation Little is known of the history of Catholicism in the Outer Hebrides prior to the 11th century. One thing which can be said with confidence, however, is that Christianity came to the region via the Irish. The Church had been established in Ireland no later than 400. Irish chieftains established the Kingdom of Dál Riata in what is today Argyll and the Inner Hebrides around the year 500. Moreover, tradition tells us that the Irish monk St. Columba established an abbey on the small island of Iona off the coast of Mull in 563. These are the foundations of the spread of Catholicism to the Western Isles. Supposedly St. Barr (or St. Finbarr), Bishop of Cork, visited the island of Barra and gave it his name in the late 500s. The ruins of a 12th-century church, Kilbar Church (Cille Bharra), can be seen today in the village of Eoligarry on Barra. There is speculation that this church was built atop an older chapel dating back to