Visit Lake Titicaca
Ticked off in December 2015
What it is
Lake Titicaca is one of the highest navigable lakes in the world at around 3,800 metres.
How to do it
Visit the Uros floating islands from Puno in Peru, or Isla del Sol from Copacabana in Bolivia.
Top tip
Stay overnight with a family on Amantaní or Taquile.
My experience
Ticked off, but the full story is still to be written up.