Inter v AC Milan. Celtic v Rangers. Tottenham v Arsenal. Boca v River. City v United.
There's nothing quite like a football derby. It is more than just a football match. It is a day when the city comes to a stop. When colleagues become enemies. When families split. The fans hate each other, and violence can sometimes happen.
Derbies are about more than just winning the match; they're about bragging rights. It means that, until the next time they meet at least, one team will be walking taller and singing louder than the other.
But what is a derby? And what makes them so intense?