Here's a rollercoaster that me and my friend made. My friend did all the command blocks and redstone while I did the design. 
This was for our English project, in where we had to make any theme park ride, choose a genre for it, explain why you did this in the ride and other stuff that English lessons normally teach you that isn't grammar. 

Anywho, unlike the other groups who did their rides in real life with cardboard, we decided to make ours in Minecraft and record it, and our teacher was cool with it.  It's a bit rushed, as you will see from the start of the ride you will see a bit of the castle and the end of the ride. We don't really plan on finishing it as our teacher is fine with it anyway and currently we're on our summer break. 

If you think some things look weird, it's because my friend built this using the Dokucraft High resource pack (Which can be found here: dokucraft.co.uk/downloads/dokucraft-high/ )

The video will be up soon.