The winter solstice is here. Today marks the shortest day in the Northern Hemisphere, while last night was the longest night of the year. This has been an important event for millennia, with evidence of celebrations going back as far as 10,000 BCE. Some of the world's most famous Stone Age monuments, including Stonehenge, are aligned with the point that the sun rises or sets on the winter solstice. Traditionally, it was a time for feasting and lighting of fires to symbolize the darkest day of the year. Ancient Germanic tribes celebrated the winter solstice by bringing evergreens into their homes as a symbol of the returning light and the coming spring.