an open air swimming pool or an outdoor swimming pool

[zoobinshid]

Hello my dear masters,
would you please tell me which one is better to say? or if there is a better way of saying insted of them?

1) an open air swimming pool
2) an outdoor swimming pool

thanks in advance,

[Tdol]

They're both OK. I wouldn't say 'open air swimming pool' for one in somebody's garden, though; just for a public one.