Cumbemayo

Cumbemayo is an aqueduct, and one far older than the Inca. A channel roughly a handspan wide and shin deep was cut into solid volcanic rock and carried for kilometres across a high plateau, turning at sharp right angles that slow the water and cut its erosive force. The precision of the cutting is the thing worth going for. Around it stand the frailones, columns of weathered volcanic tuff that the guides call friars, and a nearby rock shelter holds petroglyphs. The whole plateau sits at about 3,500 metres in bare grassland, and the walk follows the channel from one section to the next.

What you actually see

• The carved channel - a hand-cut aqueduct with deliberate right-angle turns.
• The frailones - a plateau of tall eroded volcanic columns.
• The petroglyphs - carvings in a rock shelter beside the canal.
• The plateau itself - open high grassland with views back over the Cajamarca valley.

When to go

May to September, the dry months, when the track in is passable without drama and the plateau is not fogged in. Most organised tours leave Cajamarca in the afternoon, which is often the cloudiest part of the day; a morning taxi buys better light and fewer people. Bring wind protection in any season.

Honest expectations

It is high, cold and windy, and the exposure hits people who arrived in Cajamarca the same day. The road is rough and slow for twenty kilometres. The canal is a narrow groove in grey rock and looks like very little without a guide explaining what was cut and when. The walk crosses uneven, slippery stone. Dating is debated, so anyone quoting you an exact century is guessing.

Nearby

Cajamarca's centre, the Otuzco burial niches and the Porcón dairy valley.