It's the stuff of childhood dreams.
As the sun begins to break through the darkness in Laos' Nam Kan National Park, the cries of wild, black-crested gibbons echo through the jungle air.
Crawling out of our mosquito-net covered beds, perched high in wooden treehouses that tower over the jungle floor, we grab our binoculars for a closer look as these lively animals leap through the trees in the distance, the leaves around them shaking wildly as the branches bounce up and down.
It's an incredibly special moment you won't find anywhere else in the world made possible by the Gibbon Experience, a tourism-based conservation project that kicked off in the late 1990s as a response to illegal logging.
At a height of 30-40 meters above ground, the Gibbon Experience's eight treehouses are the tallest in the world, according to staff.
But here's the best part (or worst, if you're not a fan of high-speed thrills). The only way to access them is via zipline.
"We have a 15-kilometer network of ziplines," explains Yann Gourmelon, the Gibbon Experience's GIS specialist.
"It allows us to bring customers deep into the forest very, very quickly. The longest line is 600 or so meters, which means you'll be zipping along superfast for about 50 seconds enjoying the views."
(Check out some of this high-speed action in the above video.)
The Gibbon Experience offers three types of tours, all of which include a mix of trekking and ziplining.
The Classic Tour and Waterfall Tour are both three days and two nights. There's also a two-day, one-night Express Tour.
We picked the Classic Tour -- it's the most relaxed option -- given we had three kids under 12 and one teenager in our group.
(The minimum age to join the Waterfall and Classic tours is eight, while kids 12 and up can join the Express Tour, which is more challenging.)
All eight treehouses are equipped with electric lights.
On day one, we journeyed from the Gibbon Experience office in the small town of Ban Houayxay to the Nam Kan National Park by truck, a 2.5-hour drive. After a brief trek to the equipment camp we were set up with ziplining harnesses and gloves.
Accompanied by two guides, we made our way through the well-trodden jungle trails, trekking and ziplining, ending the day at our designated treehouse, much to the disappointment of the kids, who would have preferred to keep zipping well into the night.
Day two was spent much in the same way -- trekking through stunning jungle scenery and enjoying exhilarating (and at times terrifying) zipline routes, while also visiting other treehouses in the Gibbon Experience network.
All of the treehouses are made with wood reclaimed from poachers and are equipped with electric lights. Beds, covered with mosquito nets, are basic but comfortable.
Each treehouse washroom is open air (though shielded from other parts of the treehouse) and has its own fresh water shower.
Laos-style meals are cooked up in a neighboring village and delivered to the treehouses by staff -- via zipline, of course -- along with fresh local fruits and local snacks.
So how do they select the trees that will hold these incredible treehouses?
Gourmelon says considerations include location, height and whether there are gibbons nearby. Too high and it's difficult to supply fresh water. Too low means visitors would miss out on the views.
"About two years ago we changed the way we design treehouses," he explains.
"Before we had to bring an architect to spend a lot of time in the tree. It's not very comfy and not easy if you want to take accurate measurements of the angles and curves everywhere. It wasn't very efficient. You could make beautiful treehouses, but it took a lot of time."
Travelers sleep in the open air. Mattresses are covered in mosquito nets at night.
Today, he says they use drones to fly 360 degrees around the tree, taking pictures at different angles, saving them weeks of time once spent drawing it all manually.
Through the use of photogrammetry software, they're then able to generate a 3D model of the tree, which is used to work on the design of the actual treehouse.
In terms of construction, there are several techniques used depending on the tree structure and shape. For instance, some are suspended on rope wires, others set on wooden consoles.
As for build times, Gourmelon says it depends on the size of the structure though on average it takes about six months to complete one treehouse.
Some are multi-level, allowing for a bit more privacy at night, while others make up for their lack of space with incredible views of the jungle canopy dozens of meters below.
The visible part of the iceberg
The Gibbon Experience was born of a desire to conserve the area's valuable ecosystem and protect it from pressures like Illegal logging, commercial cropping and excessive slash-and-burn practices.
It all started in 1996 when founder Jef Reumaux arrived in Laos and went trekking in the area. While on a hike he spotted black-crested gibbons and took some images.
It turned out that particular breed of gibbon, endemic to the area, was critically endangered. It was then that they realized they had to find a way to conserve these luscious forests.
Black-crested gibbons are a critically endangered species.
"But how are you going to find funds to protect the area, because you need to pay forest rangers, and the government at this time didn't have a lot of money," says Gourmelon.
Then came the idea to create a series of trails, treehouses and zipline networks -- "the visible part of the iceberg," he says -- as a way to bring people and money to the forest.
The first treehouses and ziplines opened in 2004.
By working with the local authorities, the Gibbon Experience project area, covering 136,000 hectares of mixed deciduous forest, was officially designated a national park in 2008 by the Lao National Assembly.
Today, the Gibbon Experience employs more than 120 full-time staff, many from the neighboring villages.
Profits are spent on various park projects. These include funding for the National Park Patrol team, which is focused on illegal logging, hunting, bomb fishing and land use and reforestation schemes in both the national park and its surrounding farmland.
Know before you go
Travelers should pack lightly, as they'll need to carry their backpacks with them on the first and final day of the trek.
Larger luggage can be stored back at the Gibbon Experience office.
Wear old shoes, as the trails can get incredibly muddy.
Bring your own large bottle of water, which you can refill in each treehouse.
A Gibbon Experience treehouse at night.
Remember to charge all of your camera batteries/phone ahead of time, as there are no electrical outlets in the treehouses.
Extra stuff to consider bringing: Binoculars, playing cards and ear plugs (both for jungle sounds and potential snoring treehouse mates.)
Zipline safety: Since beginning zipline operations in 2004, there's been one fatality
Guides are strict about making sure the line is clear before the next person uses it by sending signals across the cable, though do take care to make sure you're using your own equipment correctly and all knots are secure as you won't always be in the presence of a guide.
Gourmelon says all of the equipment is imported from France, goes through rigorous regular inspections and is changed at the slightest hint of wear and tear.