St. Ciaran's church was the first of Clonmacnoise's churches. And like all the buildings that would follow it for at least three centuries it was built of wood.

This is the smallest of all the churches. It has antae and putlockholes, and is built largely of sandstone in a masonry style similar to the cathedral with which it was probably contemporary. The church measures 3.8 x 2.8 metres internally. The walls have shifted badly out of plumb, probably due to earlier burial activity.

Few features survive, the south wall south half of the west wall being modern.

This was traditionally known as the burial place of St. Ciaran, the soil of which was formerly in great demand for its alleged cures beneficial properties. In 1684 this church was roofed and a relic, known as St. Ciaran's Hand, was kept in it. the print of 1738 shows only the rafters of the roof in place.

Several legands exist conserning soil from St. Ciarian's grave. one of which was a local tradition says that if one carries a little soil it will provide protection against storm or tragedy at sea.

This story tells of how St. Colmcille visited Ciarian's grave and took away some soil as a reminder of his friend. But on his return journey to Iona his ship was caught in a severe storm. Colmcille prayed and cast some of the soil into the sea, whereupon the storm ceased and the ship finished its journey in safety.

Another legand says that soil from St. Ciarian,s grave scattered in the four corners of a field will ensure that that fields crop will grow to maturity.