How Do You Get To The Little Minecraft Track Across The Rymek Plateau

I saw it in my play through, but I want to know how to go ride it, so where do I go to get to there?

 

there's a little cave near the lift mechanic on that platform, go through it and towards the minecart track, then there's a button on the left side of the cave which summons a minecart you can hop on to get across the track

 

Thanks 10char