Chile
Chile's bicameral Congress consists of a Chamber of Deputies (lower house) and a Senate (upper house). The country is divided into 60 electoral districts for the lower house and 19 senatorial constituencies for the Senate. Each electoral district or senatorial constituency elects two representatives. That is, 120 deputies and 38 senators, in total. Chile is the only country in the world with two-seat electoral districts.
Read more about this topic: List Of Electoral Districts By Nation