[4] The north east rises steeply from the sea to a height of 548 feet (167 m) at Mynydd Enlli,[5] which is a Marilyn, while the western plain is low and relatively flat cultivated farmland.

[7] The island has been an important religious site since the 6th century, when it is said that the Welsh king Einion Frenin and Saint Cadfan founded a monastery there.

Bards called it "a direct path to heaven" and "the gates of Paradise",[18] and in medieval times three pilgrimages to Bardsey were considered to be of equivalent benefit to the soul as one to Rome.

[9] Many people still walk the journey to Aberdaron and Uwchmynydd each year in the footsteps of the saints,[23] although today only ruins of the old abbey's 13th century bell tower remain.

[27] The Suppression of Religious Houses Act 1535, on the orders of Henry VIII, resulted in St Mary's Abbey being dissolved and its buildings demolished in 1537.

[21][28] In the 16th century, Bardsey was owned by Sir John Wynn (an ancestor of the Newborough barons), who was standard bearer to Edward VI at Kett's Rebellion in Norfolk in 1549.

[30] Carreg and Plas Bach are separate buildings, but the remaining eight were built as semi-detached houses, each pair with outbuildings set around a shared yard.

The trust is financed through membership subscriptions, grants and donations, and is dedicated to protecting the wildlife, buildings and archaeological sites of the island; promoting its artistic and cultural life; and encouraging people to visit as a place of natural beauty and pilgrimage.

Oats, turnips and swedes were grown; goats, ducks, geese and chickens kept; and there is a mixed flock of sheep and Welsh Black cattle.

][citation needed] A gnarled and twisted apple tree, discovered by Ian Sturrock growing by the side of Plas Bach, is believed to be the only survivor of an orchard that was tended by the monks who lived there a thousand years ago.

Bardsey Lighthouse stands on the southerly tip of the island and guides vessels passing through St George's Channel and the Irish Sea.

[30] The island was declared a National Nature Reserve in 1986,[45] and is part of Glannau Aberdaron ac Ynys Enlli Special Protection Area.

Nationally important flowering plants include sharp rush, rock sea lavender, small adder's tongue and western clover,[13] and the rare purple loosestrife is found in places.

[50] The leafcutter bee, named after its habit of cutting neat, rounded circles in rose leaves, used to seal the entrance to its nest, is native.

Hundreds of seabirds, including razorbills, guillemots, fulmars and kittiwakes, spend the summer nesting on the island's eastern cliffs, the numbers reflecting the fact that there are no land predators such as rats or foxes to worry about.

[12] On a dark moonless night an eerie cackling can be heard across the island as 30,000 pairs of Manx shearwaters, [52] come ashore to lay and incubate their eggs in abandoned rabbit warrens or newly dug burrows.

The currents around the island are responsible for flushing in food-rich waters, and the Whale and Dolphin Conservation Society has been carrying out surveys since 1999 to find out which areas are particularly important for feeding and nursing calves.

[56] However, against king Love's wishes, the Wynn family sold the crown to the Merseyside Maritime Museum in Liverpool, England in 1986[57] where it was stored until 2000, when it was requested by Gwynedd Council to display in a 'special exhibition'; it has since been loaned to Storiel gallery in Bangor.

[54] At the outbreak of the First World War, the last king, Love Pritchard, offered himself and the men of Bardsey Island for military service, but he was refused as he was considered too old at the age of 71.

Wildlife artist Kim Atkinson, whose work has been widely exhibited in Wales and England, spent her childhood on the island and returned to live there in the 1980s.

[60] Her play Hugo was inspired by her stay, and she has produced two novels, Atyniad (English: Attraction), which won the prose medal at the 2006 Eisteddfod; and Twenty Thousand Saints, winner of the Oxfam Hay Prize, which tells how the women of the island, starved of men, turn to each other.