The Great Cavern (Templo de la Luna): Route Guide

A shrine the mountain swallowed

Almost no one who photographs Machu Picchu from the Guardhouse knows the Great Cavern exists. It sits out of sight, on the back of Huayna Picchu — the sugarloaf peak that rises behind the citadel in every postcard — where the granite folds into a deep overhang. The Inca masons read that hollow as sacred and built into it: fine ashlar walls, niches and a carved throne-like stone tuck under the living rock, half cave and half temple. Locally it is the Templo de la Luna, the Temple of the Moon, though no one can say with certainty which rites it held.

What makes it special is exactly what makes it hard to reach. The cavern is on the far side of the mountain from the city, so getting there is not a detour but a full descent down the back of Huayna Picchu and a long climb back. It rewards the small number of travellers who want the citadel's quietest, strangest corner — a place where the masonry seems to grow out of the cliff and you are likely to be entirely alone.

How you actually get there

The Great Cavern is not part of any standard citadel circuit. You reach it only by taking the longer of the Huayna Picchu options — the variant that, instead of simply climbing the peak and returning the same way, drops down the mountain's far side, passes the Temple of the Moon, and loops back. Because of that, the cavern shares the Huayna Picchu permit: a separate, capped, named add-on ticket that sells out earliest of everything at Machu Picchu, often weeks or months before your dates in dry season.

In practice that means three things have to line up: you secure the right Huayna Picchu add-on (confirm at the point of sale that the version you are buying includes the Moon Temple loop, as naming varies and the rules have changed before — verify current wording), you allow far more time than a standard visit, and you arrive fit and unhurried. This is the most committing walk on offer at the site, and it cannot be improvised on the day.

• The cavern rides on the Huayna Picchu add-on, tied to the lower royal circuit — decide and book it early.
• Confirm the specific route includes the Templo de la Luna loop; not every Huayna Picchu ticket does.
• Entry windows for the climb are fixed by your permit; you cannot wander up later in the day.
• Bring your passport — the add-on, like the main ticket, is checked by name at the control point.

The walk: steeper than the peak itself

Trekkers who have done both often say the Moon Temple loop is harder than simply summiting Huayna Picchu, even though it goes lower. The reason is the return. You descend a long, steep staircase down the back of the mountain to the cavern, and then every metre you have dropped you must climb back up to rejoin the trail. The path is narrow, frequently wet under the canopy, and includes Inca steps so steep they function as ladders, with stretches where a fixed cable or wooden rung is the only handhold.

It is exposed in places, slick when damp, and very lightly travelled, so there is rarely a queue and rarely much company — wonderful for solitude, less forgiving if you are nervous on heights or short on stamina. Budget far more time than the distance suggests; the climb out is where people run down their reserves.

• Expect ladder-steep Inca staircases, fixed cables in places and a tiring climb back up.
• Surfaces are slick in the wet season — the canopy keeps them damp even between showers.
• It is one of the least-crowded walks at the site, which also means least support if something goes wrong.

At a glance

Use this as a quick gut-check before you commit a precious Huayna Picchu permit to the longer loop. Details like exact capacities, prices and opening windows change — treat the figures you find on official sources as current and verify before booking.

• What it is: the Templo de la Luna, a worked-stone shrine inside a granite overhang on the back of Huayna Picchu.
• Ticket: reached via the longer Huayna Picchu add-on (lower / royal circuit) — a scarce, early-selling permit.
• Difficulty: hard — the steepest, most exposed walking at the site, with a long climb back out.
• Crowds: among the quietest corners of Machu Picchu; you may have it to yourself.
• Seasonality: sections can close after heavy rain or for maintenance — verify the route is open.
• Who it suits: confident, fit walkers who want solitude and unusual masonry; not for the altitude- or height-anxious.

Should you add it — or skip it?

Be honest about what you want from the day. If this is your one visit to Machu Picchu and you most want the classic frame, the Intihuatana and the temples, spend your time and energy on the citadel itself; the Moon Temple is a connoisseur's detour, not a headline. But if you have stood on the Guardhouse overlook before, or you crave the site's quietest, most mysterious stones and you trust your legs, the Great Cavern is one of the most atmospheric places in the entire sanctuary.

Whatever you decide, decide early. The permit that unlocks it is the first thing to go, and there is no buying it at the gate. Lock the ticket, then build the train, the bus and the night in Aguas Calientes around it.

What the Great Cavern (Temple of the Moon) actually is

The Great Cavern route leads to one of Machu Picchu's least-visited and most intriguing structures: the Temple of the Moon (Templo de la Luna), built into a natural cave on the far side of Huayna Picchu. Here the Inca did what they did best — worked with the rock rather than against it, fitting exquisite cut-stone masonry into and around a grotto in the mountainside, with carved niches, a throne-like seat and finely fitted walls that rank among the most refined stonework anywhere at the site. It sits well below and beyond the main citadel, hidden on the back of the peak, which is exactly why so few visitors ever see it. The name 'Great Cavern' refers to the cave setting; the temple within it is the prize.

Reaching it is a serious undertaking. The trail drops steeply from the Huayna Picchu side down the back of the mountain and then climbs again on the return — a long, demanding loop on narrow, exposed and sometimes slippery Inca steps through cloud forest. It typically takes several hours round trip and is far harder than the climb up Huayna Picchu alone. The reward is solitude and a genuinely special structure; the cost is time, effort and a head for exposure. This is a route for fit, sure-footed walkers who want depth over the postcard view.

• The Temple of the Moon: refined Inca masonry built into a natural cave behind Huayna Picchu.
• One of the site's most remote, least-visited and finest pieces of stonework.
• A long, steep, exposed loop — down the back of the mountain and back up — taking several hours.
• Harder than Huayna Picchu alone; for fit, sure-footed walkers wanting solitude over the classic view.