CAIRO, EGYPT – December 17: The Karnak Temple during the winter solstice on December 17, 2015 in Luxor, Egypt. Egypt’s Karnak Temple was built in alignment with the solstice, in order to focus light on a shrine to the sun god. Ancient Egypt’s sprawling temple of Karnak was constructed in alignment with the winter solstice at Luxor more than 4,000 years ago. Similar alignments can be seen from Angkor Wat to Machu Picchu. (Photo by David Degner/Getty Images).