The town of Springfield has a lot of iconic places, among those the Simpsons’ home at Evergreen Terrace, which has a peculiar design. Most rooms in the house have been shown multiple times, but there’s one in particular that has only appeared in five episodes. Created by Matt Groening, The Simpsons began as a series of animated shorts in The Tracey Ullman Show in 1987. After three seasons, it was developed into a half-hour prime time show and made its official debut in 1989.

The Simpsons has been unstoppable ever since, becoming the longest-running American scripted primetime TV series with 31 seasons (and a 32nd one already confirmed), and expanding to other media such as film, video games, and comic books. The series follows the daily lives of the Simpsons family and other colorful citizens of Springfield, which have become part of pop culture along with their most frequently visited places, such as the Kwik-E-Mart, Moe’s Bar, and (of course!) the Simpsons’ home.

Related: The Best Simpsons Episodes In Season 1

Located in Evergreen Terrace, the Simpsons’ home is a two story house with a garage, basement, and all the normal rooms a house has. The family spends most of its time in the living room (the one with the TV, of course) and the kitchen, and while most fans could easily name all rooms in the Simpsons’ home without much trouble, there’s one room they probably won’t remember as it has only been shown five times.

The Simpsons’ Rumpus Room Has Only Appeared Five Times

The Simpsons rumpus room

The Simpsons’ home has a rumpus room that is located next to the kitchen. The hallway on the right side, next to the fridge, leads to the mysterious room, which has a small TV, a bean bag, and an armchair. The room has appeared in season 2’s episode “Three Men and a Comic Book”, season 3’s “Radio Bart”, season 4’s “Brother from the Same Planet”, season 5’s “Lady Bouvier's Lover”, and then jumped to season 28’s “A Father’s Watch”. This “secret room” might be the most family friendly place in all the house, as it has the TV, the chairs, and various toys (most likely Maggie and Bart’s) can be seen all over the floor.

Given that the room has only appeared in those episodes (and partially in a brief shot in season 2’s episode “Itchy & Scratchy & Marge”), many fans don’t know it exists, and are very confused when seeing cutaways of the house – and it doesn’t help that the design and proportions of the house seem to change all the time. This and how little the rumpus room is used were mocked in season 25’s episode “White Christmas Blues”, with Marge saying there’s a recreation room off the kitchen but “sometimes it’s there and sometimes it isn’t. Our house is very odd that way”. Why the recreation room is rarely featured in The Simpsons is unknown – maybe the writers forget about it, or it simply works best to have them watching TV in the living room – but this mysterious room has become part of the many eccentricities of the series.

Next: The Simpsons: Why The Opening Credits' Cash Register Changes Amount