Bullpen

What is bullpen? It is a small area that is similar to mound. (Mound is little hill where pitchers throw balls.) Bullpen's main purpose is to provide a safe place for relief pitchers to warm up. Pitchers have to warm up because it protects injuries and body to work out for pitching. The maximum number of pitchers that bullpen can hold is two. However, if there are empty spaces, hitters usually warm up at there, too. It is usually located next to dugout (place where coaches and players rest), but sometimes is also located in outfield.
(Dugout)

(Bullpen)