Archaeologists have found many ancient sites that line up with the winter solstice sun.
Here are 11 sites that line up with the winter solstice, and what experts think about them.
Newgrange, County Meath, IrelandPeople celebrating the sunrise at Newgrange on the morning of the winter solstice in 2018.
ShutterstockOne of the most famous examples of ancient architecture lining up with the winter solstice is in Machu Picchu, Peru.
"From the winter solstice the days are longer, which was a metaphor of the rebirth of the deceased," he said.