The 77th parallel north is a circle of latitude that is 77 degrees north of the Earth's equatorial plane, in the Arctic. It crosses the Atlantic Ocean, Europe, Asia, the Arctic Ocean and North America. It is the northernmost integral parallel that passes through continental mainland (namely the Taymyr Peninsula of Siberia).
At this latitude the sun is visible for 24 hours, 0 minutes during the summer solstice and nautical twilight during the winter solstice.