I used to work for a company that had an office in London and I thoroughly enjoyed my time there each visit. Office was in the business district of London and walking distance to everything like London bridge, markets, pubs, tower of London and many more. They have some fire Indian food spots there too. Locals seemed very welcoming to tourists for the most part and this kid even showed me a skate park hidden in plain sight near Big Ben which was pretty cool, it was one of my first nights there and I was just walking around in the early evening on my own. There are most definitely shady parts of the city but I feel that's the norm for most major cities out there. A co-worker was warning me of the red light district type area in town lol.
Kind of miss working for that company just because I got to spend a week in London each trip and was even able to expense an AirBnB in a cool part of town that was similarly priced to the plain hotel they had me stay in my first time.