Automatic teller machines (local name: cash machines) are everywhere in United Kingdom. Pretty much anywhere you look there will be an ATM. United Kingdom has one of the highest ATM densities in the world.
You do not need a chip & PIN card to use an ATM — your standard magnetic card will work fine.
The exchange rate you'll get on an ATM is usually the best one you'll get. You’ll pay fees, but you’ll still get a better rate than you would exchanging cash at a bank or exchange booth.
ATMs category is available in production API version 2.