In Cusco, at 3,800 metres above sea level, we got a glimpse into what we'll be like in 60 years. Even the slightest incline saw us slow to the pace of geriatrics. Long slopes took every bit of energy we could muster and we'd stop at the top of the hills breathless and as red as cheerio sausages.

Altitude is a killer. We managed to avoid actual altitude sickness thanks to endless cups of coca tea (made from coca leaves) at the hotel. But it gets you in other ways.

It saps your energy, attacks your breathing - and imagine my horror when Tim said it's best to avoid alcohol in the first few days. Dinner wasn't the same without that one glass of wine.

And we were hit with another surprise in Cusco - the cold. It was a very strange experience to go from the heat in Chile to the chilly air in Peru. We donned woollen hats and hooded jumpers. I bought a scarf and a jacket fit for the snow.

Next stop: Battling the constant assault of people selling things on the streets of Cusco and why I could never say no.

Check out more photos from my trip in my Flickr album.

Find out about Peru.

Read more of Kelly's blogs.