<P> There are "almost as many definitions of Eastern Europe as there are scholars of the region". A related United Nations paper adds that "every assessment of spatial identities is essentially a social and cultural construct". </P> <P> While the eastern geographical boundaries of Europe are well defined, the boundary between Eastern and Western Europe is not geographical but historical, religious and cultural . </P> <P> The Ural Mountains, Ural River, and the Caucasus Mountains are the geographical land border of the eastern edge of Europe . </P> <P> In the west, however, the historical and cultural boundaries of "Eastern Europe" are subject to some overlap and, most importantly, have undergone historical fluctuations, which make a precise definition of the western geographic boundaries of Eastern Europe and the geographical midpoint of Europe somewhat difficult . </P>

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