San Alfonso del Mar is a massive resort found within Argentina and this location is also famous for housing the largest pool in the world. Perched upon the shores of the Pacific Ocean, this pool holds an incredible 250 million litres of water. However, this water is directly pumped and filtered from the sea as opposed to being fresh water. It was built in 2005 and analysts estimate that the total cost was approximately $1.5 billion dollars. It offers a maximum depth of 35 metres and the pool is just over one kilometre long. It is found approximately 100 kilometres west of the city of Santiago.