The 80th parallel south is entirely located in Antarctica. However, the closest continent other than Antarctica closest to it is South America.
The continent at 0 degrees latitude and 0 degrees longitude (the intersection of the equator and prime meridian) is Africa. The point is located in the Atlantic Ocean, off the coast of Ghana and Liberia.
Asia
The nearest city is Burgos, Spain.
Cuautla, Morelos, Mexico.
The nearest city is Singapore.
Antarctica, but when we're talking about degrees north or south, we say latitude, but when its degrees east or west, we say longitude Antarctica is located at 80 degrees south latitude.
The South Pole is at 90 degrees S latitude and is located on the continent of Antarctica. Apart from Antarctica, the nearest continent to the South Pole would be South America.
The continent at 0 degrees latitude and 0 degrees longitude (the intersection of the equator and prime meridian) is Africa. The point is located in the Atlantic Ocean, off the coast of Ghana and Liberia.
From South Africa, travelling westerly along the 30 degrees line of latitude, the nearest continent is the east coast of South America.
Asia
Since California is located in USA, the nearest country east of USA and at 40 degrees north latitude is Portugal.
Ottawa, Canada
The nearest city is Burgos, Spain.
Cuautla, Morelos, Mexico.
That point isn't located on any continent. It's far out in the Pacific Ocean, about 900 miles from northern California, 980 miles from the nearest point in Alaska, and 1,300 miles north of Honolulu.
The nearest city is Singapore.
That point is just inside the western boundary of Afghanistan, about 31 miles east of Zabol, Iran.