King's Cross Platform 9¾ and dozens of “Harry Potter” locations dot the country; London is also James Bond's home base.
The London Underground, opened in 1863, is the world's oldest — locals simply call it “the Tube.”
Swap the Camden crowds for the lanes of Hampstead. A data eSIM makes it easy: Citymapper for the Tube, contactless payment on buses, and review-checking before a pub.