On the Thirteenth Day of Yule in the year 1153, Earl Harald Maddarðarson of Orkney was travelling from Stromness to Firth when he was caught in a blizzard. He and his companions took shelter from the storm in the famed Neolithic burial mound Maeshowe, where, interestingly, two of his party went mad. This delayed the travelers for so long, reports the Orkneyinga Saga, that they didn't reach Firth until well after dark.
Dating from around 2500 BCE, Maeshowe was well known to the Vikings, who ruled the Orkneys for more than 300 years. Carved into the stones of the mound's central chamber is one of the largest known collections of runic inscriptions in Europe. According to the longest,
Crusaders broke into Maeshowe. Líf Earl's-Cook carved these runes. To the northwest is a great treasure hidden. It was long ago that a great treasure was hidden here. Happy is he that might find that great treasure. Hákon alone bore treasure from this mound.
Maeshowe is famed for its orientation to the Winter Solstice sunset. For the last few years, on the morning of Midwinter's Eve, I've tuned in to the live on-site webcam to watch. What I saw there amazed me.