Most French rulers since the Middle Ages made a point of leaving their mark on a city that, contrary to many other of the world's capitals, has never been destroyed by catastrophe or war. In modernising its infrastructure through the centuries, Paris has preserved even its earliest history in its street map.[citation needed] At its origin, before the Middle Ages, the city was composed around several islands and sandbanks in a bend of the Seine; of those, two remain today: the île Saint-Louis, the île de la Cité; a third one is the 1827 artificially created île aux Cygnes. Modern Paris owes much to its late 19th century Second Empire remodelling by the Baron Haussmann: many of modern Paris' busiest streets, avenues and boulevards today are a result of that city renovation. Paris also owes its style to its aligned street-fronts, distinctive cream-grey "Paris stone" building ornamentation, aligned top-floor balconies, and tree-lined boulevards. The high residential population of its city centre makes it much different from most other western global cities.