Hey @adamdynamo
Netlify sites are served from multiple CDN nodes around the world, so the site is served to the node closest to the requester. As per this post and this (slightly older) post changing regions for functions is possible (if on Pro or higher). Also refer to this post which states
our CDN will always be global and we have no provision for hosting only locally.
If you have any further questions, do not hesitate to reply.