The stones are real enough. You can take a bus to Calango and La Capilla, from the back of the market in Mala, next to the kiosk selling cakes. You may find Wilma sitting beside you, heading to her chacra, her brothers and her mother. Looking out of the window you will see the broad river winding through farmland. The hill sides above are bare and rocky, but look closely and you may see traces of the narrow old track clinging to the cliffs.
If you get off the bus at the corner before the bridge, buy some bottled water from the old woman sitting on the balcony. You will need it. As you stride up the valley, look out for the farmers breaking the soil with mule drawn ploughs. Listen to the rippling water in the high irrigation canals, and the calls of the hawks circling overhead.
The llama femurs will still jut out like coat pegs in the empty rooms of the deserted villages you pass along the road.
And after two hours, three if you stop to explore some of the ruins, you will reach the stones.
If you are lucky or smart, the water will be low, green and slow-moving, in a deep pool. You can wade across if you are careful, placing your feet between the slippery round boulders. The old man may be planting cassava, or cleaning the shallow grooves through which rivulets of water trickle between the apple trees.
And then you will see the stones.