Hi! There is an excellent John Betjeman poem about Slough.
We host at a number of places - there are some servers in Slough (many of our global regions are actually hosted in suburbs rather than the city proper. It’s the most common place for datacenters). Most of our servers are actually in London (within zones 1 and 2, not just inside the M25!) though when it comes to this region - Docklands and the City (or very close to it in Farringdon). These are just where our colo providers have space rather than us doing any magic to get people routed to a specific DC that’s closer. If you deploy to LHR you could get hosted on any one of these sites 