Where are all the garbage cans??

We spent 2 days walking all over London and now 3 days in Leeds and you can never find a garbage can when you need it. I don't know how they keep both cities clean because there are just no garbage cans. In the Chicago and NY subway there is a garbage can every 5 feet. We were in probably 10 subway stations and 4 train stations and I didn't see a single garbage can.