Drill straight through the center of the Earth from Madrid, Spain and you'd surface on the exact opposite side of the planet — its antipode.
Madrid's antipode sits at 40.42°S, 176.30°E, in the southern hemisphere, east of Greenwich. That places it in or near the Pacific Ocean.
It lies roughly 20,015 km from Madrid — 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 Madrid.
Madrid's antipode is a rare one: it actually lands on solid ground, about 1 km from Mahoe, a peak in New Zealand. Most cities don't get that lucky — antipodal land pairs are uncommon since water covers about 71% of the globe.
Antigea's live map shows the satellite view, the closest Street View, and the local time on the other side of the world.