Fifty feet or so north of the chapel site is a standing stone known as Clach A'Pheanais, or The Penance Stone, which may have been used for flagellation or other acts of penance by parishioners following confession at the chapel.
The chapel is roughly oblong, measuring 32' by 20', with walls 3-4' thick, and is enclosed within an oblong enclosure. At one corner of the chapel is a small stone cross. At the west end is a small basin possibly used for holy water.
Several cruciform stones (rough stone crosses) have been found on the site. No one seems to know when Cill Chaitriona was built; if local tradition is correct and it was founded by monks from the first phase of monastic settlement on Iona, that would suggest a date between, say, 600 and 800 AD. Or, if the monks came from the second phase of monastic activity on Iona, that would place the building of the chapel at a time after 1200.