The next day, after my quiet moment at dawn, we all explored the ruins. Our mule driver knew a little about the site, but for the most part we guided ourselves. I had Spanish-language photocopies of government materials; the one book I had found in English was filled with beautiful photographs and too heavy to tote up the mountain. We saw only six other tourists.

Choquequirao, like all important Incan cities, is laid out in alignment with the movements of the sun and the stars. One building on the central plaza has nooks in which the mummies of important citizens were placed, and it is onto these nooks that the first rays of dawn fall each day.

The city’s central temple is a small rectangle on the other side of the plaza with evenly spaced depressions for altars and stone hooks where the priests hung their raiment. The most striking feature about the temple is how tiny it is; like those at Machu Picchu, it could fit perhaps 20 worshipers and had very little of the architectural grandeur of a mosque, a church or a synagogue. But then, an attempt at human grandeur here, in the shadow of the jagged jungle peak Corihuayrachina and facing arid, domelike mountains so gargantuan they make clouds look small, would seem redundant at best.

Although Choquequirao is more spread out than Machu Picchu, and therefore less photogenic, the promontory on which it lies reaches its zenith with a ceremonial hill behind the plaza, a smaller version of the rugged mountain seen in every photograph of Machu Picchu. The hike up takes just a few minutes but affords a 360-degree view of the ruins and the surrounding landscape. The curious feature of the hill is that it was scalped, flattened and denuded of vegetation by the Incas so their priests could perform rituals there.

On the other side of the plaza, the city climbs steadily uphill following a carved stone aqueduct where water will again flow in a few years as restoration progresses. It soon reaches a zigzag set of terraces resembling a giant’s staircase. Obsessed as they were with building cities on top of mountains, the Incas developed terraces like these to grow crops. Choquequirao has quite a few scattered about, long rice-paddy-like structures imposing angular order on the wild cliffs, but these narrower terraces were special. The priests probably used them to grew the special coca that figured heavily in their rituals. (Modern Andean peoples still use the coca leaf, not to make cocaine but for the mildly euphoric coca tea that appears to occupy the same space in their culture as our coffee, alcohol and aspirin wrapped into one.)

A path from the central plaza leads to the residential district, a complex of newly exposed simple four-walled houses that the jungle is already doing its best to reclaim. The place had a creepy “Indiana Jones and the Temple of Doom” vibe, heightened by the rustling of unknown animals in the brush. That glancing-over-your-shoulder fear, the sort of adrenaline rush you hope for at ancient ruins, is still attainable at Choquequirao.