Uro-Settlement at Lake Titicaca#
The Uros islands at Lake Titicaca are just five kilometers west from Puno port. Their purpose was originally defensive. Only a few hundred Uros still live on and maintain the islands; most have moved to the mainland.
The reeds at the bottoms of the islands rot away fairly quickly, so new reeds are added to the top constantly (about every three months, in the rainy season even more often). The islands last about thirty years.