We’ve been thinking lots lately about Northern Ireland and how much we enjoyed our time there. One of our truly memorable experiences was a trip to Boa Island in Fermanagh to see the mysterious carved figures in the Caldragh graveyard.

Despite the fact that this is one of Northern Ireland’s most important archaeological sites, we had the place to ourselves when we were there, in October 2016. In fact, it looked like any peaceful rural graveyard, with higgledy piggledy gravestones behind a hand-forged iron gate, lush grass, and an air of benign neglect.

But there’s one big difference – in this remote place are two of the most enigmatic carved figures on the Island of Ireland. The first one has two faces – it’s been called a Janus figure, or simply bilateral, carved in a style that is reminiscent of Early Medieval carvings, but also different. Different enough so that one can see these as pre-Christian figures, and that is how they are most often interpreted.

Boa Island itself may be named for the Goddess Badhbh (pronounced Bov), a potent character in Irish mythology. The figures do not bring saints or clerics to mind – there are no croziers, no fingers raised in blessing, no tonsures or crosses. We’ll look at the bilateral figure first. It has two faces, back to back, with a groove in between. The groove collects water and in recent years people have started to leave coins in the puddle formed by the groove, perhaps echoing its original purpose. The heads are joined at the side by herringbone or plaited lines that may represent hair.

One side has been interpreted as male and some point to a stylised penis that rests between the legs. Although I have seen photographs of this side when it had been recently cleaned, where a carved element is denoted as the penis, it is not in any way obvious now that the statue is once again covered in lichen and badly weathered, with moss growing in this area. The face is long and triangular, the mouth open and the eyes wide and staring. Two arms cross across the body, over a belt which runs around both figures.

On the other side the mouth is open and a tongue protrudes. Apart from that, the figures are almost identical. The statue is broken just below the belt on this side, so it is impossible to say that there are any female, or indeed male attributes present.

The carving has been mounted on a plain base but leaning against it is what might be the original base, or part of it. If it is, then the arms extended down into hands, resting on either side of the base.

There is a second figure, brought here from nearby Lusty More Island. This one is much more worn, or perhaps not even totally finished, but it’s possible to see that it bears a strong resemblance to the others in its triangular face. The arms are not crossed but appear to be holding something. Visitors leave coins in front of this one.

What does it all mean? In short, we don’t know, but current consensus appears to fall in the area of calling these figures representations of pagan deities. The smaller figure, rather than holding something, may be female and pointing to her genitals. This would place it in the tradition of the sheela-na-gigs, although presumably much earlier than the majority of sheelas, which are thought to be medieval.

Whatever they are, they have inspired poets and artists – even filmmakers. One of our favourite films, the marvellous Song of the Sea, has taken much of its artistic design from prehistoric Irish art, including the Boa Island figures. Watch this teaser for the movie and see if you can spot the Boa Island figure at 46 seconds.

And the poetry? Seamus Heaney, of course, himself from Northern Ireland, drew inspiration from the landscape around him and often wrote about archaeological themes. His poem, January God, captures the mysterious sense of the two-faced God and makes a shift to summon the idea of Cernunnus, the antler-headed pagan god of wild things depicted on the Gundestrup Cauldon.

Then I found a two-faced stone

On burial ground,

God-eyed, sex-mouthed, its brain

A watery wound.

In the wet gap of the year,

Daubed with fresh lake mud,

I faltered near his power –

January god

Who broke the water, the hymen

With his great antlers

There reigned upon each ghost tine

His familiars,

The mothering earth, the stones

Taken by each wave,

The fleshly aftergrass, the bones

Subsoil in each grave.