For many years the icon for London was "Big Ben." But the London Eye is edging out the big clock as the instantly recognized symbol of the city. At over 400' of height (135m), the wheel rotates at one revolution per half hour—slow enough so it doesn't stop to load or unload its passengers. On the clearest of days, it is said that you can seem for 25 miles. Even when it is not perfectly clear toward the horizon, the view straight down can certainly get one's attention!