Lake Titikaka is 3810 meters high, the highest navegable lake in the world, located roughly half in Bolivia and half in Peru... The tiwanakus considered it sacred for centuries... so did the incas after them... and still today it's considered sacred by local bolivians and peruvians...
Why it is sacred? Well... both tiwanaku and incas considered nature sacred, specially when it was beautiful... and Lake Titikaka has lots of beauty to offer...
In the bolivian side, Copacabana town contains ruins and beautiful hills with amazing rocks and view points. The Island of the Sun contains all of that as well... combined with an ancient Inca trail and the magical consideration of being the Island of the Sun... In "Isla del Sol" there are no roads, no cars, no motorbikes... just peasants... for transportation of goods, just donkeys... terraced hills (inca style) for agriculture... and all kind of farm animals... beautiful!. In a way, it was like going back to the past... no cars, no stress, no noise... just people taking care of the fields and animals in such a beautiful and magical island...
In the peruvian side, I loved Taquile island, with a culture in itself, all dressing in a similar way... jeans haven't yet arrived here!... and they solve their little disputes by asking advice from the elders of the island...
As well in the peruvian side, I got really surprised with the Uros Islands. These Islands are floating islands, built by the Uros people using a very common sea weed from the lake... The Uros "went floating" at the time of the Incas... to avoid paying taxes, they were poor and could not afford the taxes living in the land, so they fabricated their floating islands and worked as fishermen... Today, it's still really impressive, there are around 5000 Uros people in around 100 islands... but it's so touristic that the locals are just too much looking for the tourism and are able to speak english and sing songs in 6 languages just for us... that was weird!... but that's the way it is... the world is very small now, and just as we need to earn money somehow, they find new ways to earn money as well... no matter how we would like them to remain as they were...
But change is the nature of things... the Uros and all cultures change with time... otherwise there would be no history books, neither a way to improve things, nor a way to make them worse... and just as things and cultures change with time... we also change with time... Once I read that "changing is not to become a different person, it's just adding on top of what already is... which by the way... is what you have been doing all of the time"...
