Some of Titicaca's islands are not really islands at all; they are built, and their builders can rebuild them if they need to move.
Woven land
The Uros people construct floating islands from layers of dried totora reeds, a plant that grows thickly in the lake's shallows, anchoring the mats with rope to the lake bed and adding fresh reed to the surface regularly as the bottom layers rot away. Tradition holds the practice began partly as a defensive strategy, letting communities relocate their islands to open water to keep distance from more powerful groups on the mainland, including, in some accounts, the expanding Inca state itself.
Boats from the same plant
The same totora reed is bundled and lashed into boats, used for transport and fishing on the lake for a very long span and still built today, partly for continued use and partly for craft demonstrations aimed at visitors, which has become an income source alongside fishing and reed handicrafts.
Height as well as origin
Titicaca sits at roughly 3,812 metres above sea level, commonly cited as the highest lake in the world navigable by large commercial vessels, a practical claim distinct from the mythological one that the Inca creator god Viracocha brought the sun, moon and the first Inca ruler into being from its waters.