The Underground. The Tube. The magical carpet that whisks people hither and thither in London. Yes, it can be congested. Yes, you can encounter delays or station closures. But it's still an amazing system.
The Underground is over 150 years old. It has 270 operating stations on 11 lines. It handles 1.3 billion passengers per year.
Now, you do need to learn its secrets, its quirks, its ways. The most basic skill you need is learning to read the system maps. At first glance the map looks like a plate of multi-colored spaghetti, but, in fact, it's a diagram that displays the entire, glorious, complex, confusing, system at a glance. The man who designed the map in the 1930s, Harry Beck, did so on his own time since his superiors thought his idea wouldn't work. But he realized that, since the trains run underground, people didn't care where, exactly, the tracks were; they only cared about the relative locations of the stations.
In Central London it's important to realize that some stations are quite close together. For instance my flat is roughly equidistant from Marble Arch, Edgeware Road, Lancaster Gate and Paddington stations. Which station I should use depends on which line I need to take for my destination. Picking the better of two nearby stations, even if one is a few blocks farther away, can save you time and the trouble of transferring between lines.
The Tube is now cashless. Even a single-trip ticket must be purchased before you approach the gate to the station. But if you're using the Tube every day, as I am, an Oyster card is the way to go. This is a pre-paid card you simply touch to the card reader on the gate. The great thing is that fares have daily caps; once you pay the maximum, you card is not debited for the rest of the day, no matter how many times you travel.
Riding the Tube requires you to steel your nerves for the sensory overload of bustling, public, urban life. People walk quickly, they know where they're going, and tourists need to fit in. So you need to plan your journey, follow the signs, and be ready to move. When you ride the escalators stand to the right so people can pass you on the left. And be ready to climb stairs, lots and lots of stairs. My FitBit indicates I climbed 190 steps today, and I only took the Tube twice.
Many stations have attendants who will patiently answer your questions and point you in the right direction, even to places near the station. When you emerge from the station it's important to orient yourself and figure out which way you need to walk to your final destination.
I guaranteed that after you return home from a visit to London, you'll wish your town or city had its own Underground.