Ganvié is a community of around 3,000 stilted buildings on Lake Nokoué in Benin. It has a population of between 20 and 30 thousand people. The town on the lake was settled several hundred years ago to protect residents from slavery, as local religious tradition forbade attacking anyone on the water. See more pictures and video of Ganvié at A Welsh View. Link
(image credit: Hugo!)
Its kinda cool that each house has its own Island.