Whether it's a fourth-grade game of dodgeball in the gym or the NFL's Super Bowl, the midfield line of a sporting event is always the center of the drama. But in northeastern Brazil, there's a soccer stadium with a very unusual center line. Not only does it divide two opposing soccer teams, it also divides two different halves of the world.

You can't get there from here.

Macapá is perhaps the most remote of Brazil's 26 state capitals. Located between a vast rainforest and the banks of the Amazon River, it's actually separated by the sprawling Amazon delta from the rest of the nation. There is no highway connecting Macapá, a city of some half a million people, to any other state of Brazil.

Macapá is "the Capital of the Middle of the World."

The city takes its nickname from the fact that it straddles the Equator. One of its foremost tourist attractions is the Marco Zero monument, a 100-foot-tall concrete sundial on the southern edge of the city. A red stripe runs east from the tower for a mile down Avenida Equatorial, marking the imaginary line that separates the Northern from the Southern Hemisphere. There's a circular hole through the top of the sundial, so when the sun sets on the spring and fall equinoxes, a sun-shaped orb moves due east down the avenue, tracing the Equator.

The score is zero-zero here at the Big Zero…

Next door to the Equator monument is the football stadium where top-level local teams like Amapá Clube and Trem Desportivo play their home games. Officially, it's named Estádio Milton Corrêa, after a late regional soccer official. But everyone calls the field Zerão, meaning "the Big Zero." That's because it's located exactly at zero degrees latitude, squarely on the Equator.

Cheer on your favorite hemisphere!

In fact, the stadium is built so that the midfield line follows the Equator exactly. In every soccer game there, each team isn't just defending its own goal. One side is defending the Northern Hemisphere, and the other side the Southern Hemisphere, like a giant game of Risk. But the geopolitical overtones switch in the second half, of course, when the teams swap goals.

Explore the world's oddities every week with Ken Jennings, and check out his book Maphead for more geography trivia.