The verticality that is Macchu Picchu!
We spent a very nice night in Aguas Calientes, despite the town band (literally a marching band) that played until midnight! The train ride to Aguas Calientes was in the dark, so we didn´t see what a steep valley we were in. After a quick panic about not enough money, and losing 200 soles (about 60 dollars - lost, not stolen), we were so pleased to find a cash machine in this tiny little village at the base of Macchu Picchu. I guess it makes sense because the whole village is geared towards tourists, but I was still blown away by our remoteness and the availability of cash any time! 
Machu Picchu called our name early the next morning and we were on a very early bus (6:30 a.m.) bound for the ancient site. The switchbacks up the mountain were truly a whiteknuckle experience, especially when two buses met nose to nose. I am amazed that they have the capacity to handle over a thousand tourists a day! Luckily we arrived hours before the tourist trains arrived and turned the place into Inca Disney World.
Once inside the gate, we were lucky and chose a hiking path that took us straight to the Sun Gate - the classic Macchu Picchu picture shot. The whole site of Macchu Picchu is far bigger and cooler than I ever imagined. It is literally perched on a mountain top with sheer dropoffs on either side!! We found out later it was more of a retreat center and place for ceremonial gatherings, but still, it could house over 2,000 people!! It was very romantic to wander around the grounds, poking your head into what were once houses, and looking out at the snow-capped peaks in the distance. Llamas wandered the whole site - we figured out later that they were the lawn mowing service!!
After a few hours of wandering and mega photo-documentation, we registered for our hike up Huayna Picchu - the peak behind the ruins site. What an incredibly vertical experience that was!! We were on the original Inca steps up the mountain (with a few added cables and ladders for safety!), and they were literally steps all the way. I lost count after a while, but as I was being passed by elderly people and people with kids on their backs, I thought to myself - wow, how out of shape are you? We did make it to the top for increcible views of the valley below (straight down, nothing to keep you from falling at least 2, 000 or 3,000 feet to the river!), the ruins, and the snow-capped peaks all around!
Getting down was no easy task because by this time, the tourist trains had arrived and there were so many people coming up the trail that it felt like a dance - you first, no, you first... We caught the 2:00 bus back down to the valley floor in time to have a lunch of pizza and pisco sours, and then to catch our 3:55 train back to Cuzco.
After all that hiking/scrambling, we were very ancy and wiggly on the 4 hour trainride. About 1 hour out of Cuzco, you can catch a bus in one of the villages above the city. We did just that, and were down to Cuzco in 20 minutes! If you can imagine what we looked like, dirty, hiking clothes on and limping - we fell into bed!