I am a stadium known for being the home of a Major League Baseball team with a unique seating configuration due to the presence of a nearby railway line. My outfield walls have unusual angles and measurements, and I was opened in the early 20th century. A notable feature includes a manual scoreboard that is still used to this day. Which iconic stadium am I?

1. I am one of the oldest ballparks still in use in MLB.
2. My dimensions include a famous 'Triangle' area in left field.
3. I've hosted several World Series games and a few MLB All-Star Games.
4. A brick wall in the outfield is famously known as 'The Green Monster'.