The Ur(os) Seastead
The tall totora reed grows in the shallow waters near the shores of the lake. The roots of these reeds are cut into chunks and when dried, roped together until they form a large mass. They are then anchored with poles driven into the bed of the lake. Layers of reeds are stacked one on top of the other across the surface to create a base upon which the Uros construct their small homes and communal buildings.
The platforms feel sponge-like underfoot but these islands have a lifespan of around 20 years. Should there be disputes between families living on the same island it is easy to cut a single home off and float it to another island.
Hat tip, MR.