"So how was Machu Picchu", you're probably asking by now - but we're mostly doing this chronologically, and there are a few more steps before we get to the big famous stuff. All the guides make a very big thing of saying you should acclimatise to the altitude for at least two days before doing the Inca Trail. Most people seem to do this in Cusco, as it's where you fly in to and where all the tour agencies are, but we decided to go to Ollantaytambo, about half way down the Urubamba valley. This turned out pretty well: it's high enough to get used to things (around 2800m above sea level - higher than Machu Picchu and a significant 600m lower than Cusco) but not so high as to be a huge shock to the system, although we both had minor headaches for the first day. It's also where the train to Machu Picchu goes from, so we were spared having to get up so early when we did go.
The modern town of Ollantaytambo spreads along the lush valley floor, surrounding the Inca-era centre, which has some of the oldest continually-occupied houses in South America. An amazing amount of the hillsides were clearly terraced, although most of the terraces are no longer used for farming.
The first photo above is of the Pinkuylluna storehouses, about half an hour's climb up the side of the mountain to the north-east of town. They're built on a very steep slope for ventilation: apparently huge quantities of food were stored here in Inca times. We walked up to Pinkuylluna on our second day in town to get used to the heights and saw almost nobody.
On the north-west side is the remnants of the Inca fortress, built up a hill with a commanding view of the valleys below. This site is on all of the tours, and so the best time to go is when it's actually raining, otherwise there will be hundreds of people climbing everywhere. There's a lot of old remains that are now mostly buried beneath several feet of silt that was washed down from a mountain in a torrential storm a couple of hundred years ago. Some of them have been partially excavated: enough to understand that there was some very sophisticated hydrological engineering going on, but not enough to understand it fully.
Inca stonework is rightfully celebrated: the religious sites have incredible masonry with enormous blocks fitted together without any visible gaps. Most of the stonework, though, is more like the one on the right (which is actually from Machu Picchu). In the middle is one of the terrace walls from Ollantaytambo, where you can see that some of the stones have been shaped to fit together better, as it's a high status site. I should really have made sure that there was something for scale in these pictures: the large stones are three or four feet across. The largest stones go up to 50 tons each, and were moved from quarries that could be miles away, using only log rollers.
Here's a picture looking down the Urabamba valley towards Ollantaytambo. The mountain on the left looks pretty barren - I think this is because there's a microclimate there that means it doesn't get as much rain as the one on the right, which seems to be getting all the rain here. It also has signs of old terraces a good 500m above the valley floor, and diagonal paths leading up to them: this marginal-seeming land isn't farmed any more, but it seems as though the Incas took every opportunity to grow crops that they could. Not far behind where I was standing to take the photo, however, the landscape changes to rolling hills vaguely reminiscent of the Swiss Alps.
This looks very fertile and productive - and it mostly is, except for the fact that it's actually too high up to grow corn: only potatoes and quinoa will survive up here at 3500-3800m above sea level. There are now small, rather sad, mountain towns, and also the Inca ruins of Chinchero. Most of the economy there seems to be subsistence farming, with a good sideline in selling hand-woven alpaca fabrics. You can go and have a tutorial in spinning, dyeing, and weaving, and if you buy something the ladies will sing and dance you to your car, no matter how embarrassed you are.
Finally, some notes on logistics: we went to Ollantaytambo from Cusco by shared taxi. This took around two hours and cost us 60 soles, because we rented the whole taxi rather than waiting for two more people to share it with. It would have been a pretty cramped ride (one in the front and three in the back of a small car) but it's 15 soles each if you do it that way.
The easiest way to get into the fortress is with a boleto touristico that costs 130 soles and is valid for 16 sites in Cusco and the Sacred Valley over 10 days. You can buy partial tickets for 70 soles a pop, but they're only valid for one or two days, so it really makes sense to cough up for the whole package. We had to show our passports when buying the ticket, but never again afterwards.
We actually spent five nights in Ollantaytambo: two before Machu Picchu, and three afterwards. We should really have done this the other way round, to have more time to acclimatise first, but it worked out fine. There's definitely enough in the neighbourhood to keep you busy for two or three days if you want to pack it all in as quickly as possible.
There are two ATMs in town, but they won't let you take out more than 450 soles at a time, and charge a hefty S/18 commission, so if your hotel is the type that slaps on 5% extra for paying with a credit card you might want to stock up on cash in Cusco.
Food notes: Apu Veronica does great, reasonably priced local food. Chuncho, on the Plaza Mayor, is the only high end option in town. The bakery on the corner of the square makes great empanadas - just be ready to chat to the baker while your order is prepared.