Are S3 buckets region specific?

Solution 1:

The user interface shows all your buckets, in all regions. But buckets exist in a specific region and you need to specify that region when you create a bucket.

Solution 2:

S3 buckets are region specific, you can check http://docs.aws.amazon.com/general/latest/gr/rande.html#s3_region to get the list of end-points based on the region

From the doc on creating S3 bucket

Amazon S3 creates bucket in a region you specify. You can choose any AWS region that is geographically close to you to optimize latency, minimize costs, or address regulatory requirements. For example, if you reside in Europe, you might find it advantageous to create buckets in the EU (Ireland) or EU (Frankfurt) regions. For a list of AWS Amazon S3 regions, go to Regions and Endpoints in the AWS General Reference.

Also from UI, if you look at the properties for each of your bucket, you will see the original region