Drill straight through the center of the Earth from Rome, Italy and you'd surface on the exact opposite side of the planet — its antipode.
Rome's antipode sits at 41.90°S, 167.50°W, in the southern hemisphere, west of Greenwich. That places it in or near the Pacific Ocean.
It lies roughly 20,015 km from Rome — about as far apart as two points on Earth can possibly be. And the relationship is symmetric: the antipode of that spot is, of course, right back here in Rome.
Rome's antipode falls over open water, in or near the Pacific Ocean — water covers about 71% of the globe, so antipodal land pairs are rare. The nearest named place is Forty-Fours, a small island in New Zealand, roughly 715 km away.
Antigea's live map shows the satellite view, the closest Street View, and the local time on the other side of the world.