The United Kingdom, also known as Britain or the United Kingdom of Great Britain and Northern Ireland, is a European region with a long and storied history. The first modern humans (Homo sapiens) arrived in the region during the Ice Age (about 35,000 to 10,000 years ago), when the sea levels were lower and Britain was connected to the European mainland. It is these people who built the ancient megalithic monuments of Stonehenge and Avebury.[i]