stonehenge_vid_midsommar_1700_f_kr_nordisk_familjebok Published September 6, 2014 at 411 × 499 in stonehenge_vid_midsommar_1700_f_kr_nordisk_familjebok In the 1960s Gerald Hawkins thought it was a solar and lunar calendar. Stonehenge on midsummer, 1700 BC. Nordisk familjebok (1918), vol.27, p.115 [1]. [Public domain], via Wikimedia Commons