[3][5] The island is known for its early Christian connections to Brendan the Navigator and Columba and for bedrock containing rare formations in relation to the global Sturtian glaciation.

The eastern side is relatively low-lying but in the west the land rises and then drops "sheer into the Atlantic" in cliffs of metamorphosed limestone up to 60 m (200 ft) high.

[14] However, Adomnán notes that Brendan the Navigator set sail from Ireland to visit Columba and found him en route at Hinba.

[14] Undaunted, writing in 1973 W. H. Murray insisted the identification of this island with Hinba "is agreed by all authorities" including William Reeves (1857) and Skene (1876).

[19] The main ruins overlook the rocky landing place on the south coast, which is guarded by a line of skerries called Sgeirean Dubha.

About 90 m (300 ft) east of the chapel is the Clochain - two partly reconstructed beehive huts that are the most visually striking remnant of the early settlement and the finest examples of this type of structure in Scotland.

[6] Closest to the landing site is Tobar Challuim-Chille or Columba's Well, a natural spring that flows into a basin contained by a large slab of stone.

[7] The double beehive cell, standing at more than 3 metres (9.8 ft) tall was probably used to shelter anchorites who had withdrawn from the world to live in isolation at the site.

[21][7] The settlement was destroyed by Viking raiders who were present in the area from about 800,[3] although its continued use was testified by John of Fordun writing about 1380, who described the island as a "sanctuary".

[24] The island remained a place of pilgrimage and burial after its abandonment and it was in the care of the Augustinian priors of Oronsay until the Protestant Reformation in 1560.

[26] Other buildings from roughly this time period include the winnowing-barn and parts of the ruin often incorrectly described as a "monastery", which was added to on successive occasions.

[22][21] The outcrops of limestone on Eileach an Naoimh give rise to fertile soils and the slope of the land makes for "verdant" south-facing hillsides.

A wide variety of flowering plants are found there including primrose, yellow flag, meadowsweet and honeysuckle.