This is the Antipodes Map (AKA Tunnel Map). It's a tool that lets you see what's on the other side of the world from any given spot on Earth.
Find where you live on the left side and zoom in. The right side shows where you'd pop out if you drilled a hole straight down through the Earth and out the other side (or vice versa).
http://www.findlatitudeandlongitude.com/antipode-map/ (http://www.findlatitudeandlongitude.com/antipode-map/)
Sadly, nowhere I've lived seems to end up anywhere interesting on the other side of the planet. Maybe you'll have better luck. All my spots ended up in the Indian Ocean, southeast of Madagascar (more or less).