Premise: Buckingham Palace ( [ ˈbʌkɪŋəm_ˈpælɪs ] ) is the London residence and administrative headquarters of the reigning monarch of the United Kingdom . London . The London Underground is the oldest underground railway network in the world . The London Underground ( also known simply as the Underground , or by its nickname the Tube ) is a public rapid transit system serving London and some parts of the adjacent counties of Buckinghamshire , Essex and Hertfordshire in the United Kingdom .
Hypothesis: London is the location of a place.
Label: ENTAILMENT