I would be surprised if there were absolutely no cultures harboring superstitions/supernatural belief, but since people tend to be insecure beings and therefore need to feel like they have some control, it makes sense they'd choose to have a belief that allows them to think they have a some control (eg through praying, karma, etc). At any rate there are countries in which the majority are atheists, such as some Nordic European countries, and certain communist countries.

There were some cultures found during World War two that had no god concept. As soon as they were exposed to other people that was ruined.

Not any place where there are populations of humans.

Yes lots, a least if you don't bother with tiny marginalized minorities. Most Buddhist and former Buddhist countries, many pre-industrial Animist cultures, China, Japan, the Czech Republic, and large parts of northern Europe where nones are fast becoming majorities.

Yes. My Aunty Joan’s house. 61 Acacia Avenue, Hartlepool. But if you are going round make sure you take a battenburg with and that it’s Mr Kipling and not one of those own label disasters.

Cleveland