The plain 3 metre High Cross is located at the site
of a 6th century monastery on a steep hill overlooking the town of Moville and Lough Foyle.

In Ireland, as Christianity flourished after its introduction in the 5th century, pre-existing pagan shrines were rededicated to this new faith. The ancient Cooley Cross is believed to be a prime example of this. It is suggested that it was
previously a pagan “hole stone”, a primitive slab
with a single hole near the top. According to
historian, Dr. R.A.S. MacAlister it may have
contained a peg serving as a gnomon of a rudimentary sundial, the vertical shadow
indicating the hour of noon. To convert it to
Christian use, the slab was cut down to form a
cross. Four semi-circular holes were carved,
creating the ring pattern distinctive in later
Celtic High Crosses. Above them, but off centre
to the rest of the design is the old pagan hole
still preserved. This irregular piercing is cut at a different angle to the other holes.