A Christian monastery was founded on the island at some point between the 6th and 8th century, and was continuously occupied until its abandonment in the late 12th century. The remains of this monastery, along with most of the island itself, were inscribed on the UNESCO World Heritage List in 1996.
Skellig Michael remained in the possession of the Order of St. Augustine until the dissolution of the Ballinskelligs abbey by Elizabeth I in 1578. Ownership was then passed to the Butler family with whom it stayed until the early 1820's, when the Corporation for Preserving and Improving the Port of Dublin (the predecessor to the Commissioners of Irish Lights) purchased the island from John Butler of Waterville in a compulsory purchase order. The Corporation constructed two lighthouses on the Atlantic side of the island, as well as associated living quarters, all of which was completed by 1826. The Office of Public Works took the remains of the monastery into guardianship in 1880, and repaired certain collapsed structures, before purchasing the island (with the exception of the lighthouses and associated structures) from the Commissioners of Irish Lights.
World Heritage List
Skellig Michael was inscribed on the World Heritage List in 1996, at the 20th Session of the World Heritage Committee in Mérida, Mexico. After being nominated for inclusion on 28 October 1995, an evaluation of the site by the International Council on Monuments and Sites (an advisory body of the World Heritage Committee), recommended that the island be inscribed on the basis of criteria (iii) and (iv) of the World Heritage List's selection criteria, which relate the cultural significance of a site. The Committee approved this recommendation, describing Skellig Michael as of "exceptional universal value", and a "unique example of an early religious settlement", while also noting the site's preservation as a result of its "remarkable environment", and its ability to illustrate "as no other site can, the extremes of a Christian monasticism characterizing much of North Africa, the Near East and Europe".
Each year 13 boat licenses are granted to tour operators who each run a single trip to Skellig Michael each day during the summer season (April to October, inclusive), weather permitting. For safety reasons, because the steps up to the monastery are rock, steep, and old, climbs are not permitted during very wet or windy weather. There are also dive sites immediately around the rock.