Lake Titicaca is the highest navigable lake in the world, at nearly 4,000 metres above sea level. It is also enormous, with just over half of it in Peru, and the rest in Bolivia.
We went on a boat trip today to see two amazing groups of people who live on islands in the lake.
The first actually live on a floating island that they built themselves!
It is built mostly from reeds lashed together, it is round and is about 25 metres across. Six families live on the island and they share all of the tasks between them.
Their ancestors have lived in this way since the 1500s, and there are currently about 100 similar islands spread across the lake.
However, the islands only last about 25 years before they start to rot and disintegrate, and then they have to build a replacement.
They make money nowadays from visitors and selling hand embroidered crafts, and I bought a beautiful table runner from a lady who was even shorter than the women on the mainland.
We went on a little boat trip on a canoe that was also made from reeds, and then watched a storm head across the water.
Luckily it was a false alarm as the storm stayed in the distance, and we left to go to our next island.
This one was more traditional and extremely beautiful, l our boat pulled up to a tiny jetty and we went ashore.
It was difficult to remember that this was a freshwater lake as it looked like a Caribbean island.
This one is also inhabited by long standing indigenous people, and it is illegal for any foreigners, or even non island dwelling Peruvians to buy land here.
These islanders also make money from visitors and selling crafts and all of the men learn how to knit at a young age and make intricately patterned hats.
The altitude made it very difficult for us to even walk around, and just walking up the path from the jetty left everyone completely out of breath and with a headache.
The locals are of course used to it and put on a little show. They then got volunteers up for a little dance, which is always my sort of thing, but I just didn't have the energy.
Apparently their bodies have adapted to have larger lungs, big hearts and extra red blood cells to pump blood faster around their bodies, or something similar.
We didn't have that advantage so struggled to make walk the two kilometres across the island to where our boat had docked.
We did still manage to admire the scenery.
It took our boat about 90 minutes to get back to Puno and our hotel and I was shattered. I haven't moved from the hotel bed since, and Darren went out to get supplies of chocolate, peanuts and fruit juice and I am feeling much better now.
My favourite photo from today.