a novice was going to Caer Dallben, and asked a sage to show him the way. They started walking. The novice grew nervous. "This doesn't look like Caer Dallben" he grumbled. "We're not there yet" said the sage. "How will you know when we're there?" "It will look like Caer Dallben." "How long will it take?" "I don't know. I've never been there." At this, the novice lost his cool. "What do you mean? How do you know we're going the right way, then?" The sage shrugged. "It's complicated." They arrived at Caer Dallben. The novice, his stress lifted, became jovial and lighthearted. "Please tell me," he said to the sage, "how you knew how to get us here." The sage said, "Though I've never been to Caer Dallben, I knew that it was a city between two cliffs, watered by rivers that flow from a mountain spring. I know it is misty in autumn and rainy in winter. I know it is near an ocean. I know it has farmland to the south." "Knowing all these things, and knowing my surroundings, I knew where Caer Dallben had to be."