Machu Picchu!

Stunning. Awe-inspiring. Overwhelming. But enough about me, let's talk about Machu Picchu.

Built on crags in the cloud forest, Machu Picchu was still under construction when it was abandoned at the time of the Spanish conquest. No-one knows why - could be disease, drought, or just the expectation of falling to the Spanish (note to self: when I create a magnificent culture, ensure it has written language to help future tourists). But the Inca left, and then Machu Picchu stayed, lonely and only visited by local villagers.

The rocks for the building largely came from the site, but the sand used in the terraces came from the river bed far below. Tonnes and tonnes and tonnes of it. Each square metre of terrace used about a tonne of sand, and there are literally thousands of metres of terrace. The unending back-breaking labour of bringing that up from the river ... I can't think of words that would actually give it justice. And that's just the sand - imagine the quarrying, shaping, polishing. All with voluntary labour. It is beyond awe-inspiring.

We all took hundreds of photos. Here are some.

Effy giving us the low-down on the town.

Effy, Mark, and a local lady who wanted to join in.

The Temple of the Sun.

Even Mark was taking pictures.

Paul checks that his brain hasn't been vaporized by wonder.

Plumbing, Inca-style.

The stone pegs sticking out is how they tied down their roofs.

The inca's used perfectly horizontal solid stone water dishes carved into the mountain rock to reflect the night sky and study the stars. We used them for a different purpose.

Maintenance of the site is ongoing, and the location of every stone is recorded electronically and also the old-fashioned way.

A view of the round rocks that they sat under the foundations, to help them withstand the rocking caused by earthquakes.

But sometimes it wasn't quite enough.

Where they brought the sand from.

Whilst they protected against earthquakes, they didn't protect against subsidence (well, no-one is perfect!). Here the soil permanently shaded by the northern wall stays wet and soft. The stones have sunk half a metre into the soil after 500 years.

The temple of the two windows. Hiram Bingham (the first scientific discoverer) clearly couldn't count.

There are more ruins on the top of that peak (we didn't even try).

Every good ruin has a few alpaca.

The only known astronomical sundial the Spaniards didn't discover and destroy.

Nicole and Kim taking in the sights.

King of all I survey.

I then went to visit the Inca bridge. I was told I wouldn't be allowed to cross - and soon found out why.

Feeling very brave. Of course, Nicole out-did me by casually standing on a rock wall with hundreds of metres of shear drop behind her. Why are women always braver than me?

A final view and pose.

Having now 'done' Machu Picchu, tomorrow is our last full day in Peru, a chance to reflect, rest, and do that last-minute shopping!