“The Uros are a pre-Incan people who live on forty-two self-fashioned floating islands in Lake Titicaca.
The Uros use bundles of dried totora reeds to make reed boats (balsas mats), and to make the islands themselves.
The larger islands house about ten families, while smaller ones, only about thirty meters wide, house only two or three.
The islets are made of totora reeds, which grow in the lake. The dense roots that the plants develop and interweave form a natural layer called Khili (about one to two meters thick) that support the islands. They are anchored with ropes attached to sticks driven into the bottom of the lake.
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; this is what makes it exciting for tourists when walking on the island.”