“The world is full of nice, ordinary little people who live in nice, ordinary little houses on the ground. But didn’t you ever dream of a house up on a tree top?” — Father, “Swiss Family Robinson”

Over the last month, that fantasy from the pages of Johann David Wyss’ classic novel has taken physical shape in Todd and Gwen Graves’ yard.

Encompassing 1,200 square feet and weighing 75,000-plus pounds, the high-up hideout gets its national reveal on Animal Planet’s “Treehouse Masters” Friday night.

(Mobile users: Click here to see a photo gallery of the treehouse)

Longtime fans of the show and host and designer Pete Nelson, the Baton Rouge family has collected Nelson’s books and calendars. So when they decided to climb into a treehouse project, Nelson was the natural person to reach out to, Todd Graves said.

The treehouse is the show’s first in Louisiana and also its largest, hence the episode title, “Triple Decker Record Setter.”

“I‘ve wanted a treehouse for the longest time, and we have a great tree for it,” the Raising Cane’s founder said.

The forts Graves and his buddies built in their youth, however, bear little resemblance to what Nelson and his crew have created for the family.

The tri-level treehouse constructed in a massive oak is approached from the ground by a sturdy staircase leading to the 12-by-18-foot living space — a roomy, lighted sunset deck with seating and a fireplace-grill combination; and an indoor gathering spot with a couch, bar, microwave, fridge, sink and flat-screen TV. A tiny half-bath is located off this room. The exterior is cypress, the interior pine. “Todd had a skylight in his first store, and he does this disco ball thing, so we have a few of those around,” Nelson said, pointing upward at the large, rectangular skylight.

More light pours in from groups of windows around the space. “A big treehouse needs to be full of windows, I think, so you know you’re in the trees,” Nelson said.

A longtime builder in Washington state, Nelson was able to shift his company to treehouse-projects-only after the national exposure gained from the Animal Planet series, he said.

“I love design, I love building, but something that’s got the scale of a treehouse that you’re done in a couple of weeks kind of thing, and you get to go, ‘Look at that,’ and move on to the next one, I love that. That and the fact that these trees are so great, trees in general. I just love trees,” Nelson said.

Having done treehouses in many states, he was nonetheless impressed with the massive trees growing in Louisiana.

“I’ve never seen trees this big,” Nelson said.

A wooden ladder attached to another part of the oak leads to the second level, where a bedroom again features lots of windows including a stained-glass one salvaged from a church that was destroyed in Hurricane Katrina; a Murphy bed and French doors opening onto a small balcony. Venture up another ladder to the top level, where a 6-by-6-foot overlook, called a crow’s nest, affords a bird’s eye view of the neighborhood near LSU.

Back down on the first level, a “Star Wars” Ewok Village-style bridge stretches across the yard from the first level to another overlook, complete with a telescope to view University Lake, at the property’s edge.

“It’s Swiss Family Robinson meets the bayou,” Nelson said, of he and the family’s vision for the treehouse.

Nelson starting getting inspiration for the project on his first visit to town, dining at the rustic Parrain’s.

“It’s that lived-in look,” Nelson explained. “We wanted to have that nostalgia, that history of the area. We got to really just express ourselves here.”

The build took three weeks, with the prefabrication of the walls the only step taking place back at Nelson Treehouse and Supply in Washington.

Everything else happened from the ground up in Baton Rouge: framing, scaffolding, electrical and waterline installation, wall finishes, flooring, furnishing, accessories.

Ductless “mini split” units hanging on the walls in the first- and second-level structures handle the heating and cooling.

“I’m kind of a nonconformist kind of guy so I wanted something exceptional,” Todd Graves said. “He (Nelson) was really good at asking us what we wanted, multi-story, different pods, the Ewok bridge or Indiana Jones bridge, that looks out over the lake.

“So he was able to take those ideas we both had and say, ‘Oh, great, we’re going to do a living room pod in this tree, and a bedroom pod, and a crow’s nest that goes high, a swinging bridge to the platform.’ It was a really neat experience,” Todd Graves said.

Gwen Graves also had a wish list.

“I wanted different levels, and things you wouldn’t expect, just the Swiss Family Robinson (look), ladders going up, and different lookouts, and Pete did it.

“We absolutely wanted it to be rustic, but with reclaimed wood from Louisiana,” she said.

Nelson used old wood from a house in downtown New Orleans for the bedroom walls, and other salvaged pieces form the second level’s weather-worn siding.

“We just wanted the whole Louisiana heritage to be melded in,” Gwen Graves said.

Both praised Nelson’s work, down to the stairs built so the family dog, Cane II, can climb them, and the kids’ slide from the first level to the ground, which the pet also takes down sitting on the kids’ laps.

“He took so much care, like this is an expression of himself. He was just really into doing it and doing it right,” Todd Graves said.

Although the couple’s children — Charleton, 10, and Sophia, 12 — were anticipating seeing the treehouse for the first time, their dad said he was more excited than anybody.

“I think the suspense for kids, it’s like Christmas or their birthday, they’re so excited to see it and I think that’s the neat part of it,” Gwen Graves added.

A neat “house up on a treetop,” Father Robinson would say.