Europe the mainland until rising sea levels cut them off. Europe lies mainly in the temperate climate zones, being subjected to prevailing westerlies. The climate is milder in comparison to other areas of the same latitude around the globe due to the influence of the Gulf Stream. The Gulf Stream is nicknamed "Europe's central heating", because it makes Europe's climate warmer and wetter than it would otherwise be. The Gulf Stream not only carries warm water to Europe's coast but also warms up the prevailing westerly winds that blow across the continent from the Atlantic Ocean. Therefore, the average temperature throughout
Atlantic Europe in close cultural contact from at least the mid 3rd millennium BC, contributing to what would emerge as the Celtic culture of the West/Central European Iron Age. Archaeologists have noted that the prehistoric peoples of Atlantic Europe presented common traits, as shown by artifacts, artistic and architectural styles found in the region which attest to at least some form of trade and/or cultural link. In addition, a number of genetic studies seem to interrelate specific groups of population in parts of Atlantic Europe in contrast with, for example, Central or Mediterranean Europe. Some examples of early cultural contact are the