The 66th parallel north is a circle of latitude that is 66 degrees north of the Earth's equatorial plane, about 61 km south of the Arctic Circle. It crosses the Atlantic Ocean, Europe, Asia and North America.
At this latitude the sun is visible for 24 hours, 0 minutes during the summer solstice and 2 hours, 47 minutes during the winter solstice.
66th parallel north Wikipedia
Starting at the Prime Meridian and heading eastwards, the parallel 66° north passes through: