Viewed from certain angles, it was visible as far away as Arthur’s castle. Viewed from a different angle, it was invisible. No one had yet figured out why this was true, but we knew it was. Great legend and great mystery shrouded the peak. Some said an ancient and holy treasure was buried somewhere on its heights. Others talked of hideous monsters lying in wait within the hill. Tales so ancient that even Merlin did not know their source told of a mundus, as the Romans would have it, on the Tor. Such a place functioned as a doorway into the underworld. I did not doubt that there was a cave beneath the Tor, but such cold dark places often excited people’s imaginations. Why, some even said that the Tor was the home of Gwyn ap Nudd, the fairy king. More important, the Tor served a critical function in Arthur’s alert and message system. Watchfires linked Dinas Emrys, the castle of Ambrosius, with the Mount of Frogs, then the Tor at Ynys-witrin, and thence to Arthur’s castle.
