Large data centres appear in specific places and in tight clusters, rarely near the people they serve. The location is chosen by a small number of constraints that override almost everything else.
Power availability comes first
A large facility draws a quantity of electricity comparable to a small town, and it needs that supply continuously rather than at predictable peaks.
The binding question is not the price of power but whether the grid at that point can deliver the connection at all, and how many years the utility needs to provide it.
Sites next to substations, generating plants or major transmission lines therefore attract development in preference to locations that are otherwise more convenient.
Cooling is the second constraint
Essentially all the electricity a server consumes leaves as heat, and removing that heat is the largest secondary cost of running the building.
Cool climates allow outside air to do much of the work for a large part of the year, cutting the energy spent on mechanical cooling substantially.
Access to water for evaporative cooling matters for the same reason, and it has become a source of local objection in places where supply is already tight.
Latency decides only some of it
Services where response time is felt directly, such as gaming, trading and video calls, need to sit physically close to their users, and those facilities cluster near population centres.
Bulk storage, backups and long-running computation are indifferent to a few extra milliseconds, so they can be placed wherever power and land are easiest.
Operators therefore run a tiered estate, with small edge sites near cities and very large facilities in remote locations doing the heavy work.
Network routes anchor the clusters
A site is only useful if abundant fibre reaches it, and fibre follows existing corridors along railways, motorways and pipelines.
Where several networks already meet, the cost of connecting is low and the choice of providers is wide, which is why exchange points attract facilities around them.
Each new building strengthens that pull, since more fibre is laid to serve it and the next operator finds the connection easier still.
Local policy settles the remainder
Planning permission, grid connection queues and the treatment of large industrial power users differ sharply between jurisdictions and change over time.
Some regions actively court the investment while others have restricted new connections because the local grid cannot absorb further load.
The result is a map that looks arbitrary from outside but reflects a fairly narrow set of places where power, climate, fibre and permission all coincide.