London Eye and the Thames River - London, United Kingdom
I have seen the London Eye several times from a distance, (so much so that it was starting to feel like a mechanized Eye of Sauron) and only passed by while I was out walking the Thames after leaving the Borough Market. There is a wonderful park nearby, that is part neighborhood jaunt, part Dolores (of San Francisco), and part street fair.
I was very fortunate then, that my second stay in London was full of beautiful weather, and I spent most of the day walking the paths lining the banks of the Thames. Finding art galleries, used book markets, and the Shakespeare Globe along the way.