If you want a good example of why including a foreground element in your landscape pictures is important, see this photo gallery of Paris shot by Pierre Petit (1886-1969), aka Yvon, “the best-known unknown photographer in France.”
View the “Yvon’s Paris” photo gallery at: NYTimes.[ via RobGalbraith ]
Sometimes, it seems the foreground is the main subject, then at other times, it seems it’s the background. Some judicious “HDR” probably applied there to get both the foreground and background details.