Treehouse of Fun

He actually builds this. Somehow.

Treehouses make a great place for kids to hang out. They're located in the great outdoors, provide a high vantage point, and are naturally secluded—but just close enough to sneak into the kitchen for sandwiches and lemonade. They make good clubhouses, and "no babies allowed" is an easy enough rule for them to make when they're up so high. Rope ladder optional—otherwise just nail a ladder of boards to the trunk. For some reason this trope is prevalent in Western Animation.

Examples of Treehouse of Fun include:

Comic Books

• The first issue of Phil Foglio's revival of Stanley and His Monster revolves around Stanley's attempts to build the world's best ever treehouse, following the instructions in a book of Fun Things For Boys he finds in the attic, without his parents finding out.
• In Crossing Midnight, Toshi jumping out of the treehouse that the twins loved playing in so much is how she discovers that she is Made of Iron.

Film

• In Sleepover, Julie and her friends have to sneak out of the house and go into her treehouse, painted in bright pink and yellow.
• Stand by Me has the boys hanging out in one of these at the beginning of the film.
• Monster Squad hold their meetings in one.
• In the movie version of Bridge to Terabithia there is one used by the main characters as refuge place from real life problems.
• Step Brothers features a traditional tree-house enjoyed by the two leads and stocked with an impressive collection of porno magazines from several decades. Eventually replaced by an even cooler tree-house made from the remains of a small boat.
• In Disney's Swiss Family Robinson, the titular family contrives to build one as a home on the island where they're stranded. Why didn't they put their ingenuity and materials toward building a boat? Rule of Cool, of course!

Literature

• George and Harold of Captain Underpants drew comics in the treehouse.
• The Magic Treehouse series have two kids, Jack and Annie that go into their magic treehouse and are transported through time.

Live Action TV

• The live action The Brady Bunch briefly had a treehouse too, just long enough for Bobby to sprain his ankle climbing up, developing a fear of heights.
• Barney and Friends, B.J. and Baby Bob are playing in it a lot, and a whole movie took place in the treehouse.
• Cory moves into his treehouse in the pilot of Boy Meets World because his brother betrays him and his parents take his brother's side.

Newspaper Comics

• In Calvin and Hobbes, Calvin and Hobbes are in the treehouse a lot. Hobbes gets a lot of mileage out of the fact he's the only one who can climb up without the rope ladder being down.

Video Games

• Click Clock Wood in Banjo-Kazooie features a treehouse in different stages of completion, throughout the various versions of the world. If you go in it once it's finished, you can find a Jiggy.
• The Hub Level/menu screen for the first world of A Boy and His Blob (Wii) is a treehouse. A really epic treehouse, with three stories as well as a lookout.
• Subverted by Cosmic Osmo. In the middle of a universe of fun, the treehouse is "a place of relaxation" with nothing but a hot beverage dispenser and some teacups on a picnic table.
• One of the earlier Edutainment computer games had a treehouse. There was a chalkboard you could draw on, and a telescope you could look through, a few links to mini-games and some 'just for fun' clicky-things. It was neat, for the time, but you tended to run through the limits of what you could do really quickly.
• Limbo has lots of treehouses. How fun they are, are left up to player's imagination.
• The PC game The Treehouse is all about this.

Webcomics

• The duo of Suicide for Hire runs their questionable business out of their old treehouse. The "fun" part is for them, as the door for customers is lined with booby traps.

Western Animation

• The treehouse of Hey Arnold!.
• One episode of South Park had the kids building a treehouse to play Truth or Dare in. Randy and Sharon both remembering playing in a treehouse is part of the subplot.
• Bart Simpson had a Treehouse of Fun, which occasionally turned into a Treehouse of Horror.
• Fairly Oddparents: Timmy Turner had a treehouse.
• Phineas and Ferb rebuilt their and Candace's treehouses in "Tree to Get Ready", with an additional feature to transform into battling robots.
• The kids of Arthur often are seen in their treehouse, or a "clubhouse".
• Codename: Kids Next Door has a huge, sky-scraping monstrosity of a treehouse as not only a clubhouse, but a secret headquarters, one of many across the globe. The KND even have a tree house on the Moon; after it gets lost to a Colony Drop in The Movie, they build a BIGGER one.
• The Brady Kids in the Band Toon of The Brady Bunch were often seen in their treehouse.
• The treehouse from Adventure Time has got to take the cake.
• In My Little Pony Friendship Is Magic, Twilight Sparkle lives in an apartment at Ponyville's Golden Oak Library, which is built into a large tree. Also, in "The Show Stoppers", Applejack lets Apple Bloom and her friends use her old tree-house as a clubhouse for the Cutie Mark Crusaders. It's a mess when they first find it, but Apple Bloom manages to fix it up.

Applejack: It's a bit broken down, but all it needs is a little TLC!
Scootaloo: Tender Loving Care or Totally Lost Cause?

• The treehouse in My Pet Monster had a Surprise Slide Staircase.
• T.J. owns one in Recess.