Five Fun Facts About Swimming Pools Five Fun Facts About Swimming Pools Swimming Pools might not be the most exciting dinner party conversation but they could just get a look in when armed with funny facts like this. The largest pool in the world is Alfonso del Mar Seawater Pool which is in Chile and is 1,013 metres long. There are over 10 million swimming pools wold wide with Australian’s building more domestic swimming pools (per capita) than any other country. An Olympic sized pool can hold approximately 3 million litres of water. It is claimed that Benjamin Franklin invented Swim Fins after he used two planks of wood in his hands to propel himself faster through the water. The first heated swimming pool was built by Gaius Maecenas of Rome in the first century BC. Gaius Maecenas was a friend of Caesar Augustus and the first emperor of Rome.