There is a great deal of conjecture about what the object is. Found in the Conwy Valley (West upper margin) near Trefriw where the local tuffs probably formed part of a pyroclastic flow from an ancient volcano. The flow, a cloud of searing hot debris, gas and rock rushed down the side of the volcano, within this mass of volcanic material were ejected masses called like 'volcanic bombs' that acquired their shape in this case owing to high rotation and velocity of forward or inclined movement.