These early gravestones and cross shaft constitute a Scheduled Ancient Monument.

Llangaffo 2 is the lower portion of a quadrangular cross-shaft and base of local quartz arenite dating to the tenth or eleventh centuries. It is now located in the churchyard on the rocky knoll to north-west of current church building, but was originally noted in 1846, to the south of the then still extant old church; it was in use as a sundial.
On the main face, a ring cross, stands out in false relief. The two narrow faces have perimeter mouldings delineated by incised lines. The undecorated base is large and roughly circular in shape. Once part of a sizable free-standing cross, there has been much debate about as to whether it is part of the same cross as Llangaffo 1 (NPRN 415199), a cross-head now inside the church. However there is no diagnostic evidence on either fragment to prove this.

Llangaffo 4 is a shaped quadrangular-section pillar of Anglesey quartz arenite. The upper part of the visible face, partly dressed, is carved with an outline Latin cross. The thick cross arms expand slightly and the armpits are almost at right angles. The shaft of this incised cross tapers and ends in a spike. This is one of at least three similar upright grave-markers from the site and may be dated to the later eleventh or earlier twelfth century. Discovered amongst ten or more cross-carved stones on the dismantling of the old church in 1846, they were originally laid out as paving stones north of the current church before being re-set in their current position in 1956.

Llangaffo 5 is a rectangular-section pillar of Anglesey Carboniferous conglomerate which tapers towards the bottom of the broad faces. Towards the top of the visible face is an incomplete plain outline Latin cross, the shaft carved in high rounded relief. It has a short expanded top cross-arm and the left horizontal cross-arm stretches to the edge of the face. The shaft terminates in a blunt spiked foot, a feature also found on other Llangaffo cross-carved stones.
Later eleventh or earlier twelfth century. Located adjacent to Llangaffo 4 north of the present church.

Llangaffo 9 is an incomplete, shaped quadrangular-sectioned pillar, now in two pieces cemented together. The upper part of the face is incised in false relief with an incomplete outline Latin cross with square armpits and rounded cross-arm terminals. It dates to the late eleventh or twelfth century.
It is located in the churchyard and set into the ground, clamped to a retaining wall north of the present church. It was first noted by the RCAHMW in 1937, lying on the ground opposite the north door of the church.

Sources include:
Edwards, N 2013 A Corpus of Early Medieval Inscribed Stones and Stone Sculpture in Wales: Volume III North Wales, AN28, 185-6.

J. Gould, University of Wales Bangor, June 2013