Fenway Park

The 37-foot-high wall in left field is universally known as the Green Monster. It drastically changes gameplay because it is much closer to home plate than typical outfield walls, turning potential home runs into singles.

The ballpark opened its gates in 1912, making it the oldest active stadium in Major League Baseball. It has served as the continuous home for the Boston Red Sox for over a century.

Fenway Park currently has a seating capacity of approximately 37,000 fans for night games. Because of its historic and constrained urban footprint, it remains one of the smaller ballparks in the MLB.

Balls that hit the wall often bounce sharply back into the outfield, allowing outfielders to quickly throw runners out at second base. However, players can still hit home runs over the 37-foot structure if they get enough elevation.