After Tarzan-swinging on a rope 50 feet above the ground and walking on a wire that felt as thin as spaghetti, I quickly learned something about myself: I would never stand a chance on American Ninja Warrior, the NBC show in which competitors race through insane obstacles.

Treetop Quest, a sky-high obstacle course that opens in Philadelphia on Saturday, proved that my "I'm not afraid of heights" attitude isn't 100 percent accurate and that my balance skills are even shakier.

The course, which contains 60 obstacles, including nearly 20 zip-lines ranging from 30 to 200 feet in length, invites you to jump, swing, and soar from tree to tree across a nearly four-acre stretch of West Fairmount Park.

"You would've drove right by and not have taken a second look at this area,"  Philadelphia Parks and Recreation Commissioner  Kathryn Ott Lovell says   of the formerly forested section once covered with invasive species that have since been cleared out. "Now, people will get to experience the park system in a whole new way, in an area that's never been exposed to the public before."

Treetop Quest has three other locations — two near Atlanta and one in Mississippi — but Treetop Quest Philly is the first in an urban environment. Just a quick drive from Center City, the adventure park invites those ages 4 and up to test their strength, face their fears, and challenge their balance, all during a 2½-hour experience fully immersed in nature.

The course has six levels, five of which are up in the trees and one of which,  the Chickpea Level, is designed for kids 4 to 6.

Level one features easy-to-navigate tunnels, cargo net bridges, and balance beams no higher than 15 feet off the ground. It's suggested that all participants start there and work their way up to higher levels and higher grounds.

Level two will take you up to 40 feet above the ground, and that's where my legs first began to shake.

"How is this only level two?" I yelled down to a staffer  while navigating a bridge of individual slats suspended like swings, each wavering with every step.

A tightrope hanging 40 feet up was to follow, offering only a single slender cable to hold on to. I gripped it hard, surprised by the fear-induced tension  starting to spread through my body.

Despite feeling slightly uncomfortable for a majority of the outing, this surprise terror Treetop Quest turned out to be quite pleasant. If the obstacle course had been easy, I  likely would have considered it lame. Instead, it's one of the few activities that seems capable of offering an exhilarating time for  parents and kids alike, making it an excellent family adventure.

(I'm left wondering, would my kid self have been more or less scared than my current self? I'm betting a lot of fearless kids will outdo their parents on the course.)

After finishing level two, you're invited to move on to a section of  just zip-lines. Less physically demanding, it offers a reprieve before level four, where obstacles hover 60 feet above the ground. One of the highlights of the final level is a cargo net that hangs straight up and down, requiring you to scale across it before reaching the next obstacle, where a standing swing awaits that you must hop on to in order to fly to the next platform.

At the end of level four, you can embark on an optional extension designed for the hardcore thrill-seeker. It features four additional obstacles, including a set of monkey bars from which your feet will dangle 35 feet above the ground.

The entire course is self-guided. All participants are put on a continuous belay system from which you cannot detach before reaching the end of the course. The belay is there to catch you if you slip off  one of the balance beams, seesaw bridges, or other obstacles. Of course, you'll never be left entirely alone. Treetop Quest personnel continuously monitor the course and are available to call on if you get too scared and want to come down.

A quick training session is conducted at the start of every experience, as is a confidential weigh-in. Participants must weigh under 250 pounds.

Tickets can be purchased in advance online at Prices vary by age: $17 for ages 4 to 6; $32 for ages 7 to 11; $42 for ages 12 to 17; and $49 for adults. Walk-up tickets are available, too, for an additional $2 above online ticketing prices.

An annual $20,000 fee and 4 percent cut of the revenue will go to the city to be used for other park programming and enhancement efforts, and 1,000  free passes to Treetop Quest will be distributed to kids in Parks and Recreation summer programs.

Note, the course is open or rain or shine, so be prepared if you buy a ticket in advance.

"The rain is just an added obstacle that adds to the fun," says Scott Ireland, operations manager of Treetop Quest Philly. "Especially for kids who love to get muddy. People usually have a blast either way."