For those who prefer a gritty, authentic introduction to the city, there is the Tube. The Piccadilly Line is a long, winding affair, particularly if you’re hauling luggage. You will inevitably find yourself pinned against the doors, navigating the sharp curves of the tunnels while trying to keep your carry-on from sliding into a stranger’s lap. It is claustrophobic, it is loud, and it is quintessentially London. By the time you reach your stop, you don't just feel like a tourist; you feel like part of the urban machinery. You’ve earned your first pint.