When you can't think of an answer when your son asks why you can't build a roller coaster in your backyard...you build one.

He's known as Coaster Dad, but others call him Will Pemble, or the coolest dad ever.

The coaster might not have loops, and it might only be 180 feet long, but his son still has the coolest backyard in the neighborhood, and some pretty awesome memories.

You can follow along the adventure and learn about the physics of a backyard coaster at the blog Will started called The CoasterDad Project. There's are a ton of videos, pictures and behind-the-scenes stories that you and your kids will love!