Italy did not exist as a state until the country's unification in 1861. Due to this comparatively late unification, and the historical autonomy of the regions that comprise the Italian Peninsula, many traditions and customs that are now recognized as distinctly Italian can be identified by their regions of origin. Despite the political and social distinction of these regions, Italy's contributions to the cultural and historical heritage of Europe and the world remain immense. Italy is home to the greatest number of UNESCO World Heritage Sites (47) to date, and has rich collections of art, culture and literature from many different periods. The country has had a broad cultural influence worldwide, also because numerous Italians emigrated to other places during the Italian diaspora. Furthermore, the nation has, overall, an estimated 100,000 monuments of any sort (museums, palaces, buildings, statues, churches, art galleries, villas, fountains, historic houses and archaeological remains).
Italy has a very broad and diverse architectural style, which cannot be simply classified by period, but also by region, due to Italy's division into several city-states until 1861. However, this has created a highly diverse and eclectic range in architectural designs. Italy is known for its considerable architectural achievements, such as the construction of arches, domes and similar structures during ancient Rome, the founding of the Renaissance architectural movement in the late-14th to 16th century, and being the homeland of Palladianism, a style of construction which inspired movements such as that of Neoclassical architecture, and influenced the designs which noblemen built their country houses all over the world, notably in the UK, Australia and the US during the late-17th to early 20th centuries. Several of the finest works in Western architecture, such as the Colosseum, the Milan Cathedral and Florence cathedral, the Leaning Tower of Pisa