The 78th parallel north is a circle of latitude that is 78 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 southernmost integral parallel north that does not pass through any continental mainland (being slightly to the north of Cape Chelyuskin).
78th parallel north Wikipedia
Starting at the Prime Meridian and heading eastwards, the parallel 78° north passes through: