Every point on earth has its opposite point, starting with the Arctic Pole and its opposite, the Antarctic (which literally means "opposite of arctic"). There's even a name for a location's opposite point -- the spot where you'd end up if you tunneled straight down through the earth. That's called the antipode, a Greek word that means "opposed foot."
Odds are very good that your antipode is under an ocean. In fact, only about 4 percent of the world's entire landmass has a dry antipode. That's partly because so much of the earth is covered by water (about 70 percent). But it's also because most of the dry land is in the Northern Hemisphere and very little of it is in the Southern. Because of that, if you live in the Southern Hemisphere. your odds of getting a dry antipode are vastly improved.
Most of North America has an antipode in the Indian Ocean between Africa and Australia, but the extreme northern part of Canada and Alaska are the antipodes to Antarctica. Hawaii is the only U.S. state that has a land antipode: Botswana in southern Africa.