Frenway Park is Francine’s idea for a new stadium for the Elwood City Grebes. It is designed solely to allow the Grebes to pitch a perfect game: the left wall is too high to allow home runs and large loudspeakers on the foul pole are supposed to intimidate the batters.
Francine has a fantasy in which she presents Frenway Park to reporters and another in which the design flaws are exposed, e.g. the Grebes cannot hit home runs either and the loudspeakers make the stadium walls shake.
Francine also builds a model of the stadium for a school project with Arthur. After she accidentally damages the model while trying to add a dome, she presents it as a historic ruin called the Frenskium.
The name refers to Fenway Park, home of the Boston Red Sox.