Both driving and walking the streets of major urban areas like London can be tricky in England. And remember, they drive on the left!
You should be OK overall in Central London, but watch out for these common scams.
The Welsh are a very proud people with a long history and aren't too pleased about being ruled by the English Monarchy, but overall are friendly folk with a love of rugby union. World Nomads gives you the guide to respecting the culture and people of Wales.