Boston Citgo sign

The Citgo sign above Kenmore Square in Boston, photographed in 2017. The 60-by-60-foot trimark went up in 1965 with more than five miles of neon tubing, and it became a landmark by accident: it shows up on national TV every time a home run clears the Green Monster at nearby Fenway Park. Boston Marathon runners know it too, because once it comes into view the finish is close.