The 64th parallel south is a circle of latitude that is 64 degrees south of the Earth's equatorial plane. It crosses the Southern Ocean and Antarctica.
At this latitude the sun is visible for 21 hours, 01 minutes during the December solstice and 4 hours, 12 minutes during the June solstice.
64th parallel south Wikipedia
Starting at the Prime Meridian and heading eastwards, the parallel 64° south passes through: