This 37.2 feet high left field wall was part of the ball field's 1912 construction and back then it was built of wood. In 1934, it was re-covered in tin and concrete. Then in 1976, it was covered once again, this time in a hard plastic.
Despite the fact that we've lived in New England for the past few years, we'd never been to Fenway Park in Boston, MA, the oldest ball field in Major League Baseball and home to the Boston Red Sox.
The stadium was built in 1912 at a cost of $650,000. Its original owner, John Taylor, said the name came from its location in Boston's Fenway neighborhood. But, his family owned Fenway Realty Company and that's widely considered the reason for the name. The team became the Boston Red Sox in 1908, adapting it from the Boston Red Stockings. The name, reportedly chosen by Taylor, referred to the red hose in the team uniforms.

Our lapse in seeing Fenway Park changed in July as that's when the Nashua Senior Center sponsored a trip to tour the ball field. It was a very warm and humid day and this outing didn't include a game. Maybe we'll do that someday on a (hopefully) cooler day.
The now-called Green Monster was constructed due to the shape of the lot when Fenway Park was built. Since the distance to the left field fence was a short 315 feet, the wall was built to prevent a ball being hit out of the park. In 1936, a 23-foot net was put in above the wall to protect storefronts on adjoining Lansdowne Street from home run balls.
It was dubbed The Wall and was plastered with advertisements as shown in this vintage 1914 photo by John F. Riley.
The current moniker was applied after the wall was painted green in 1947. It's the highest among Major League Baseball field walls and the second highest among all Major and Minor league ball fields. (The highest wall by 6 inches is the left field wall at Peoples Bank Park in York, PA.) Fenway Park is the last of high-walled major league ballparks constructed for necessity vs. novelty.
In 2003, when the 1936 net was removed, the Red Sox team's new owners recognized the allegiance that fans had to the Green Monster and added 269 metal seats on top of it.
As the photo above shows, there's a ladder visible. In earlier years, the grounds crew would climb it to retrieve home run balls from the netting above the wall. When the net was removed to add seating, the ladder was no longer. It remains as a historic icon and is the only such one in the Major Leagues.

Fenway Park and Wrigley Field in Chicago, IL, are the last two remaining jewel box ballparks still in use by Major League Baseball. Both fields have numerous obstructed view seats, due to pillars supporting the upper deck.
These seats are sold as such. They serve as reminders of some of the architectural limitations of older ballparks. From 1875 through 1903, over two dozen wooden baseball parks were constructed in the U.S. mostly of wood as owners were conscious of cost. These stadiums were forerunners of what became jewel box stadiums. After owners realized the dangers of all wood ballparks, and the sport's popularity grew, they built concrete and steel parks. These classic stadiums were smaller with a single main level and a smaller upper level supported by "I" beams.
Fenway Park celebrated its centennial in April 2012 and has been added to the National Register of Historic Places. It's the fourth smallest MLB ballpark by seating capacity, second smallest by total capacity, and one of eight fields that cannot hold at least 40,000 spectators. (Online sources gave seating as between 37,305 and 37,755.)
In 1999, plans for a new Fenway Park were proposed that would have demolished the existing stadium, except the Green Monster. The plan was controversial. Save Fenway Park groups formed to try and block the move. The City of Boston and the Red Sox never failed to come to an agreement on a new stadium. In 2005, the Red Sox ownership announced it would remain at Fenway indefinitely. The stadium has since been renovated and is projected to remain usable until as late as 2061.
We learned a lot about Fenway Park, but it wasn't the only tour stop. After lunch, the group went to another landmark, the Samuel Adams Boston Brewery. (While it's not at the ball park, there's a prominent sign there.)
Following a brief tour, there was some beer sampling. As mentioned earlier, it was a hot and humid tour day. This stop was really a thirst-quencher. (Root beer was available for any non-beer fans.)