What do you get for the girl who has everything? For Kendall Jenner's 18th birthday, the answer is an empty Six Flags theme park for her and her friends -- and obviously her family -- to cavort in.

The newly legal brunette and her krew, including sisters Kylie Jenner, Kim Kardashian and Khloe Kardashian, pranced around the empty park, which was rented out just for them, and documented the experience on Instagram and Keek. (Of course the Kardashians would use a video platform with a "K.") No employees were in the park except for the ones who greeted them as they entered, not even in the concession stands! (You mean no funnel cake? Are they crazy?!)

The measure was probably to ensure the group's privacy, despite them publicizing every imaginable thing they do on their own. The lack of crowds and lines are allowed the group to roam the grounds by car instead of on foot, which meant maximum thrill ride time. Money may not be able to buy happiness, but Hell if it can't buy adrenaline.

You can check out photos and videos from the excursion, as well as Jenner's subsequent slumber party, below -- but turn the volume down, because there's a lot of screaming!

Watch Kim Kardashian on a Roller Coaster

Watch Kendall and Kylie Jenner on a Sling Shot Ride