(Photo Credit: kendalljenner/Instagram)

A season pass to Six Flags Magic Mountain in Los Angeles costs $72.99.

How much does it cost to rent out the whole park for just you and your family? The Kardashians know the answer to that.

The family rented out the park for Kendall Jenner's 18th birthday yesterday and Kim Kardashian made sure to document all the ridiculous fun through videos on Keek. The Kardashians had the park all to themselves - "No one's even working in the concession stands," Kanye West's new fiancee said in one video.

"No one else is in the entire theme park but us and the people there to greet us," said Kardashian, 33. "And we get to drive instead of walk. This is real lazy, but this is what Kendall wanted and it is a nice surprise for her and I'm excited for her. So, happy birthday Kendall."

In another video, you get to see Kardashian enjoy a roller coaster - sitting up in the front, of course - and scream her face off. Make sure the volume is down on your headphones before watching this one.

Kardashian wasn't the only one who had some thrills. Kendall and Kylie Jenner got in on the action and experienced one ride in which they were simply flung straight in the air.

"Props to @KendallJenner @KylieJenner 4 actually riding this ride … I was way too scared," Khloe Kardashian posted.

The birthday girl posted some collages today on Instagram showing off all the fun with friends and family and a pic last night of an empty park with the caption, "All to ourselves."

Jenner's real birthday is this Sunday, Nov. 3.