London is one of the greatest cities in the world and certainly the best city in the English speaking world. I've probably spent close to 6 years in London on and off between 1978 and 2021 and absolutely love it. There is so much to do and in the center of the city you can walk just about everywhere. Staying on the tube creates a deception that certain distances are longer than they are. It takes about 40 minutes to walk from Buckingham Palace to St. Paul's for example.

On a funny note, back in about 1997 or so i was walking through Soho square where there is Tudor gazebo. I had the thought, what would happen if you were really transported back in time to Shakespeare's London? How cool would it be to be there but all that you had on you was an American Express gold card!